Visual Acuity: What is 20/20 Vision?

Visual acuity is only one in a series of factors that evaluate one's vision.

What does 20/20 mean?

One of the most frequent questions I am asked is “What is my vision?” What the patient usually means by this is “What is my visual acuity?”

Each line of the eye chart is assigned a notation in the form of a fraction that represents your visual acuity. The numerator is the distance in feet the patient is from the eye chart. The denominator represents the distance at which an eye with “normal” vision can read the same line. Interpreting the numbers is simple. If you can read the 20/40 line, you’re able to see at 20 feet what a normal eye could see at 40. And if your vision is 20/20, you can see an object from 20 feet what a normal eye sees at 20 feet. Simple!

20/20 does not necessarily mean perfect vision. 20/20 vision only indicates the sharpness or clarity of vision at a distance. There are other important vision skills, including peripheral awareness or side vision, eye coordination, depth perception, focusing ability and color vision that contribute to your overall visual ability.

Some people can see well at a distance, but are unable to bring nearer objects into focus. This condition can be caused by hyperopia (farsightedness) or presbyopia (loss of focusing ability). Others can see items that are close, but cannot see those far away. This condition may be caused by myopia (nearsightedness).

A comprehensive eye examination by a doctor of optometry can diagnose those causes, if any, that are affecting your ability to see well. In most cases, your doctor can prescribe glasses, contact lenses or a vision therapy program which will help improve your vision. If the reduced vision is due to an eye disease, the use of ocular medication or other treatment may be used.

Contrast Sensitivity

We often undergo standard vision testing by viewing eye charts in high contrast conditions, where black letters or numbers of varying sizes are sharply displayed against well-lit, white backgrounds. But the real world is full of shades of gray in which people hampered by poor contrast sensitivity can have serious problems seeing distinct images under certain conditions.

Even if you have 20/20 vision, you could have poor contrast sensitivity. Contrast sensitivity testing is important because it allows eye doctors to determine how well you function in real-world conditions where objects may "blend" and become indistinguishable in backgrounds with similar coloring.

What Are Symptoms of Low Contrast Sensitivity?

Contrast sensitivity is crispness of vision, enabling us to see objects depending on how well they stand out from their backgrounds. Contrast sensitivity is often referred to as "functional vision" beyond how well you see details on a standard eye chart.

If you have low contrast sensitivity, you may have problems with night driving, including inability to see traffic lights or spot other cars and pedestrians. People with poor contrast sensitivity also may require extra light to read, and their eyes may become tired when they read or watch television. Poor contrast sensitivity also can cause you to stumble when you fail to see that you need to step down from a curb onto similarly colored pavement.

Low contrast sensitivity also can be a symptom of certain eye conditions or diseases such as cataracts, glaucoma, or diabetic retinopathy. Anti-reflective/Anti-glare coatings and polarized filters which reduce glare can help with low contrast sensitivity.

Some eye doctors administer the contrast sensitivity test as part of a routine screening. If your eye doctor determines that you need a contrast sensitivity test, it likely will be administered after the visual acuity test that determines your ability to see details such as letters or numbers on an a standard eye chart.

Contrast sensitivity testing likely will be done while you wear your eyeglasses or contact lenses, if you require vision correction. Unlike standard visual acuity testing, both eyes are tested together to determine ability to see low-contrast objects. You will be asked to look at a low-contrast test chart, with images such as bars or dots shown during a sequence of increasingly lower contrasts until you can no longer identify.

Cataracts

Cataracts are changes in clarity of the natural lens inside the eye that gradually degrade visual quality. The natural lens sits behind the colored part of the eye (iris) in the area of the pupil and cannot be directly seen with the naked eye unless it becomes extremely cloudy. The lens plays a crucial role in focusing unimpeded light on the retina at the back of the eye. The retina transforms light into a neurologic signal which the brain interprets as vision. Significant cataracts block and distort light passing through the lens causing visual symptoms and complaints.

Cataract development is usually a very gradual process which is a result normal aging but can occasionally occur rapidly. Many people are unaware that they have cataracts because the changes in their vision have been so gradual. Cataracts commonly affect both eyes but it is not uncommon for cataracts in one eye to advance more rapidly. Cataracts are very common affecting roughly 60% of people over the age of 60. Over 1.5 million cataract surgeries are performed in the United States each year.

A cataract is not a film visible on the outside of the eye, is not caused from overuse of the eyes and using the eye does not make it worse. With cataracts, there may be a need to change eyeglass prescriptions frequently. As the cataract worsens, stronger glasses are no longer able to improve sight. It may help to hold objects closer to the eye when reading or doing close-up work. The pupil, which is normally black, may undergo noticeable color changes and appear to be yellowish or white.

When people develop cataracts, they begin to have difficulty doing activities they need to do for daily living or for enjoyment. Some of the most common complaints include difficulty driving at night, reading, participating in sports such as golfing or when traveling to unfamiliar areas; these are all activities for which clear vision is essential.

Factors which may lead to development of cataracts at an earlier age include excessive ultraviolet-light exposure, diabetes, smoking, or the use of certain medications such as oral, topical, or inhaled steroids.

Cataracts commonly occur as one of three types:

X Nuclear. A nuclear cataract occurs in the center of the lens. In its early stages, as the lens changes the way it focuses light, you may become more nearsighted or even experience a temporary improvement in your reading vision. Some people actually stop needing their glasses. Unfortunately, this so-called second sight disappears as the lens gradually turns more densely yellow and further clouds your vision. As the cataract progresses, the lens may even turn brown. Seeing in dim light and driving at night may be especially troublesome. Advanced discoloration can lead to difficulty distinguishing between shades of blue and purple.

X Cortical. A cortical cataract begins as whitish, wedge-shaped opacities or streaks on the outer edge of the lens cortex. As it slowly progresses, the streaks extend to the center and interfere with light passing through the center of the lens. Cortical cataracts often resemble the triangular-shaped sections of an orange when one is cut in half. Problems with glare are common for people with this type of cataract.

X Subcapsular. A subcapsular cataract starts as a small, opaque area just under the capsule of the lens. It usually forms near the back of the lens, right in the path of light on its way to the retina. A subcapsular cataract often interferes with your reading vision, reduces your vision in bright light and causes glare or halos around lights at night.

Macular Degeneration

What is Macular Degeneration?

Age-related macular degeneration (AMD) is a disease associated with aging that gradually destroys sharp, central vision. Central vision is needed for seeing objects clearly and for common daily tasks such as reading and driving. AMD affects the macula, the part of the eye that allows you to see fine detail and causes no pain as it progresses.

In some cases, AMD advances so slowly that people notice little change in their vision. In others, the disease progresses faster and may lead to a loss of vision in both eyes. AMD is a leading cause of vision loss in Americans 60 years of age and older.

AMD occurs in two forms: wet and dry.

What is dry AMD?

In dry AMD, the light sensitive cells in the macula slowly break down. With less of the macula functioning, central vision diminishes. Dry AMD often occurs in just one eye at first. Later, the other eye can be affected. Doctors have no way of knowing if or when both eyes may become involved. The cause of dry AMD is unknown.

What is wet AMD?

Wet AMD occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. The blood and fluid raise the macula from its normal place at the back of the eye. Damage to the macula occurs rapidly.

With wet AMD, loss of central vision can occur quickly. Wet AMD is also known as advanced AMD. It does not have stages like dry AMD.

An early symptom of wet AMD is that straight lines appear wavy. If you notice this condition or other changes to your vision, contact your eye care professional at once.

Which is more common—the dry form or the wet form?

The dry form is much more common. More than 85 percent of all people with intermediate and advanced AMD combined have the dry form. Because almost all vision loss comes from advanced AMD, the wet form leads to significantly more vision loss than the dry form.

Can the dry form turn into the wet form?

Yes. All people who have the wet form had the dry form first but the dry form can advance and cause vision loss without turning into the wet form. The dry form also can suddenly turn into the wet form, even during early stage AMD. There is no way to tell if or when the dry form will turn into the wet form.

The dry form has early and intermediate stages. Does the wet form have similar stages?

No. The wet form is considered advanced AMD.

Can advanced AMD be either the dry form or the wet form?

Yes. Both the wet form and the advanced dry form are considered advanced AMD. Vision loss occurs with either form. In most cases, only advanced AMD can cause vision loss. People who have advanced AMD in one eye are at especially high risk of developing advanced AMD in the other eye.

Who is at risk for AMD?

The greatest risk factor is age. Although AMD may occur during middle age, studies show that people over age 60 are clearly at greater risk than other age groups. For instance, a large study found that people in middle-age have about a 2 percent risk of getting AMD, but this risk increased to nearly 30 percent in those over age 75. Other risk factors include smoking and obesity. Research studies suggest a link between obesity and the progression of early and intermediate stage AMD to advanced AMD. Whites are much more likely to lose vision from AMD than African Americans. Those with immediate family members who have AMD are at a higher risk of developing the disease. Women appear to be at greater risk than men.

Amsler grid: While conducting an eye examination, the doctor or technician may ask the patient to look at an Amsler grid. This grid is a pattern that resembles a checkerboard. The patient covers one eye and stares at a black dot in the center of the grid. While staring at the dot, the patient may notice that the straight lines in the pattern appear wavy.

This kind of wavy pattern on viewing the Amsler grid is abnormal. It can be an important warning sign of what is called wet age-related macular degeneration. The macula is an area in the retina of the eye that is responsible for central (straight-ahead) vision. It deteriorates most often after age 60 resulting in age-related macular degeneration (AMD). An early sign of the dangerous "wet" type of AMD is the wavy appearance of the lines on the Amsler grid. The early diagnosis of wet AMD is critical since laser surgery is urgently needed to preserve sight.

Glaucoma

What is Glaucoma?

Glaucoma is usually, but not always, associated with elevated pressure inside the eye. Actually, glaucoma is now considered a disease of the optic nerve (optic neuropathy). Generally speaking, the vision loss in glaucoma usually occurs in both eyes though, as in many other diseases such as macular degeneration or cataracts, the vision loss may not be symmetric,. That is, one eye may be worse than the other. Vision loss due to glaucoma often begins with a subtle decrease in peripheral vision. If glaucoma is not diagnosed and treated, it may progress to loss of central vision and blindness.

Vision loss in the chronic open-angle form of glaucoma generally occurs gradually over many years, while the vision loss of acute angle closure glaucoma may occur within a matter of days if not immediately treated. Since patients with open-angle glaucoma rarely notice their gradual peripheral visual field loss, they may not visit an eye doctor until advanced changes have occurred. Unfortunately, the visual field loss in glaucoma represents permanent damage to the optic nerve and is therefore irreversible. For this reason, glaucoma is often called the sneak thief of sight.

An eye doctor can usually detect those individuals who are at risk for glaucoma. These patients are called "glaucoma suspects" and must be monitored closely for subtle changes in their visual field or in their optic nerve.

There are many risk factors for glaucoma, including family history of glaucoma, anatomical variations including narrow filtering angles or anatomical damage to the filtering angles, elevated intraocular pressure (IOP), diabetes mellitus, previous ocular trauma, injury, or surgery, use of steroid pills or eye drops, patches, injections, certain nasal sprays, excessive pigment in the front or anterior segment of the eye, many degenerative disorders of the eye such as pseudoexfoliation syndrome, extremely advanced cataract, African American heritage, inflammatory disorders of the eye such as iritis, uveitis, or pars planitis, many infectious diseases of the eye such as Herpes simplex, toxoplasmosis or an extremely thin cornea.

The eye doctor also can diagnose patients who already have glaucoma by observing their nerve for damage or detecting visual field loss with a visual field test. Patients with glaucoma must be monitored closely for the remainder of their lifetime in order to adequately treat the IOP and assess treatment effectiveness.

Computer Vision Syndrome

Computer Vision Syndrome

More than 143 million Americans work on a computer each day with up to 80 percent of them or more suffering from some form of computer eye strain, according to estimates. In addition, nearly 54 million children work at or play on a computer each day either at home or in school. Prolonged computer use can stress a child's eyes and impact his or her vision development. If you or your child spend more than two hours each day in front of a computer screen, you likely experience to some degree symptoms of computer vision syndrome (CVS). Symptoms of CVS include:

• Headaches

• Loss of focus

• Light sensitivity

• Burning/tired eyes/eyestrain

• Dry eyes

• Aching eyes

• Double/blurred vision

• Neck and shoulder pains

• General fatigue/drowsiness

• Decreased productivity/increased work errors

Computer Related Vision Problems:

The human focusing system responds very well to images which have well-defined edges with good contrast between the background and the letters and symbols on that background. Characters on a computer screen, however, don't have good contrast or well-defined edges. The eyes react very differently to electronically generated characters than they do to printed characters on a page. This is because each pixel is brightest in the center and has decreasing brightness toward its outer edges. Because of this, it is very difficult for our eyes to focus and to remain focused on these images.

The eyes focus on the characters on the screen and then, as focus is lost, they relax to a point behind the screen which is called the “Resting Point of Accommodation” (RPA). The RPA is different for every individual, but for almost everyone, it is further away from the eyes than the working distance to the computer screen. The eyes are therefore constantly relaxing to the RPA and then straining to refocus on the closer screen. The ultimate effect is similar to lifting a 1 ounce rock at arm’s length. It is easy to do for a while but try doing it several thousand of times a day. This continuous flexing of the muscles which focus the eyes creates fatigue and the aching, tired-eyes feeling or headaches which are so common after long hours at the computer. And, if you need to look back and forth between the screen, the keyboard and printed or written page and the computer screen, the problem becomes even worse. The following diagram illustrates this:

Only when the eyes can clearly focus at the plane of the computer screen without the continuous flexing of the muscles which focus the eyes can the patient experience relief from the fatiguing effects of Computer Vision Syndrome.

In addition, studies have shown that the constant effort needed to focus near objects and to sustain that focus can cause accommodative spasms during which the focusing muscles lock into position and the eyes won't relax easily or at all. This will lead to increased myopia (nearsightedness) or pseudo-myopia (functioning as if you are nearsighted when you aren't). If the cause of over-focusing is not corrected, the pseudo-myopia can become ingrained and the patient will truly become nearsighted and need to wear glasses full-time. By wearing glasses which are prescribed for the computer working distance, permanent vision changes can be prevented. Computer glasses do the work of focusing on the computer screen (at arms length) instead of the eyes having to make the effort to do so.

If you already wear regular glasses, bifocals, progressives or reading glasses, you may be tempted to dismiss the need for computer glasses. Even contact lens wearers should use computer glasses over their contacts.

Unfortunately, regular glasses are not the right prescription for computer work. Wearing bifocal, trifocal or progressive glasses forces a computer user to tilt the head back to see through the bifocal or progressive at the screen height and to move the head in and out to focus on the screen. Such repetitive mechanical motions can cause neck and shoulder pain as well as back pain and headaches. In this situation, a lens prescribed for the distance from the eyes to the computer screen eliminates the need for these constant body motions.

Progressive or bifocal glasses can be prescribed in which the upper part is prescribed for the distance to the screen while the lower area is set to focus at the regular reading distance for the keyboard and reference material. The disadvantage of this option is that far distance is blurry so you can’t use them to drive home. They are a simply a tool to use for the computer just like your printer, mouse or computer screen. If a distance correction is necessary (driving, TV, etc.), the patient must remove their computer glasses and replace them with their regular glasses.

Since most patients need a different prescription lens power in each eye to correct their vision, a standard pair of “drugstore glasses” only exacerbate the problem because they have the same power in each lens and have no correction for astigmatism or for the different distances computer users need. In addition, there is no option available in these lenses to apply a tint, a UV coating or an anti-reflective coating which are so important to success in fitting computer glasses.

What Is The Best Lens For You?

There is no one type of computer glasses which fits all or is the best prescription for everyone. Visual ability, personal preferences of the computer user, the size of the screen, the font the users selects, the type of work being done, the distance between the computer user's eyes and the monitor and lighting in the workplace are all factors which the doctor takes into consideration when prescribing computer glasses.

Most daylight or cool white fluorescent bulbs emit harsh, short-wavelength blue or ultraviolet light. This blue light is difficult for the human eye to focus due to its tendancy to scatter and cause eye-fatiguing glare. Improper lighting can account for up to 30% of the visual symptoms computer users experience. Adding an Ultraviolet (UV) coating eliminates most of the blue and ultraviolet component light. An anti-reflective (AR) coating cuts down on glare coming from the computer screen, overhead lights and windows which cause over-focusing, eyestrain and headaches. Glare is created on walls and other surfaces, reflections from the computer screen, bright light coming in from outside and bright light inside.

The AR Coat also serves as a scratch coating. No lens is totally scratch proof but an AR Coat noticeably extends the life and quality of the lens as well as improving contrast sensitivity for crisper vision.

Tints affect the perceived brightness and color of the computer screen. They also filter out the unwanted effects of certain colors (blues in fluorescent lighting for example) which have been known to cause discomfort and eyestrain for computer users. The most common tints used are beige, gray and rose.

What To Look For In Computer Glasses:

In the past, traditional eye exams for near vision have resulted in glasses suited only for reading printed material, not for viewing computer screens. Once a doctor diagnoses your computer vision problems, the next step is to prescribe computer glasses which will allow the patient to work comfortably and productively at a computer. A pair of computer glasses should include:

• The prescription for the computer screen working distance (so measure the distance between your eyes and the screen before your exam and tell the doctor what that distance is when you are being examined)

• The appropriate lens type for the patient (Single vision, bifocals, progressives)

• A computer tint

• A UV tint

• An anti-reflective (AR) coating

Other tips:

Glare screen filters may be helpful for some people, but they will not solve your computer vision problems because they only affect glare from the computer screen, not the problems caused by the constant refocusing the eyes must do when working on a computer.

Take a 10-15 minute break every hour to reduce eyestrain. Look away from the computer screen every 10-15 minutes and focus for 5-10 seconds on a distant object outside or down the hallway to relax the focusing muscles of the eye or, even better, get up and take a short walk.

When you concentrate of something visually, you blink less, about 5 times less than normal, according to studies. Staring and decreased blinking dry the eyes out. Taking frequent breaks allows normal blinking and better wetting of the eyes. Office buildings tend to be dry environments which also reduce tearing. If you are experiencing significant dryness, ask your eye doctor about artificial tears or eye drops which you can use during the day.

By modifying your work area, you can reduce eyestrain and other effects of CVS. Place written pages on a copy stand at the same height and distance from the eyes as the monitor. Properly light the copy stand. Adjust your workstation and chair to the correct height. Purchase ergonomic furniture to assure proper screen locations and posture. Poor ergonomic setup is a common cause of head, neck, shoulder, and back pain.

Place your monitor directly in front of you, not off to one side. It should be about 22 to 28 inches away from you. Make sure your monitor is just right for you, not too high and not too low. You may need to raise or lower your chair. If you reposition your chair, keep in mind that your arms should be parallel to the floor when you type, and your feet should be flat on the floor or on a footstool.

Adjust the contrast between the background and the characters on the screen by adjusting the brightness on your computer screen.

Finally, maintain good posture at your desk: keep your back straight and your shoulders back.

What Should I Know About Glare?

Vision and Glare

Frankly, most of us don’t think much about how well equipped our eyeglass lenses are to reduce potentially dangerous and fatiguing glare caused by bright sunlight or reflections. When you reduce glare, you can improve your overall quality of vision and minimize eye strain and fatigue. Transitions tints, polarized lenses and Anti-Reflective coatings in spectacle lenses help to ensure that your quality of vision is at its best at all times, all day, everyday. And the best part is, you don’t even have to think about it.

What is “glare”?

• Glare can be described as “extreme brightness” from the presence of excessive visible light.

• Glare can be distracting and even dangerous and can occur day or night in a number of ways.

• Glare can cause you to squint, resulting in eye strain, eye fatigue, reduced productivity and headaches.

There are four types of glare to be aware of:

Distracting glare

Distracting glare can be caused by car headlights or streetlights at night. It can also be as simple as light being reflected off the front of your lenses making it difficult for others to see your eyes. Similarly, it may be from light reflected off the back – or inside – of your lenses so that you see the distracting reflection of your own eyes of objects behind you in your forward field of vision. As a result, this kind of glare may cause eye fatigue, annoyance and distraction.

Discomforting glare

Glare can be caused by everyday, normal sunlight conditions. Depending upon one’s light sensitivity, this glare can be discomforting regardless of weather or time of day. It can be present in any level or intensity of light, or when moving from one lighting condition to another. Discomforting glare often causes squinting and eye fatigue.

Disabling glare

This type of glare comes from excessive, intense light that can occur when you face directly into the sun. Disabling glare can block vision because the intense light can cause significantly reduced contrast of the retinal image. The latent effects can last well beyond the time of exposure.

Blinding or reflected glare

This comes from light reflected off smooth, shiny surfaces such as water, sand or snow. It can be strong enough to block vision. Reflected light is polarized and requires polarized lenses to reduce it optimally.

If you need clear prescription lenses indoors or when driving at night, but you want the comfort of sunglasses as well then photochromic lenses may be "just what the doctor ordered."

Q What is a Transitions tint?

A. Transitions is the tint that darkens outside and lightens up inside. They adapt to the level of light they are in but do not get quite as dark as regular sunglasses.

Q. What is an Anti-reflective coating?

A. An Anti-reflective (AR) coating is applied to the lens for several reasons. Primarily, it allows the 8-15% of light which is usually reflected from a lens to pass through the lens and be used for vision to so you see 8-15% better than through the same uncoated lens. Second, it makes the lens look better. A lot better. It has the effect of making the lens “disappear” so others don’t see it and they won’t notice the edge thickness of the lens as much. Third, it reduces glare which is a real problem for those with cataracts or macular degeneration and it is exceptionally beneficial for those who work on a computer, drive (especially at night) or work under fluorescent light.

Q. What is an Anti-scratch coating.

A. This one is pretty self explanatory but, with the newer Anti-reflective coatings and their levels of scratch resistance, Anti-scratch coatings are not as necessary as they once were (unless an Anti-reflective coating is not applied to the lens).

Q. What is a bifocal?

A. A bifocal lens is one that has the old fashioned line in the lens which helps to

magnify letters, etc., to make them easier to read. The top of the lens focuses your distance vision (driving, movies, TV) and the bottom focuses at reading distance (books, newspapers, computer keyboards).

Q. What is a trifocal?

A. It is a lens which has two lines in the lens; the top of the lens helps to see far away (driving, TV, etc.), the first segment focuses at an intermediate distance (Computer screens, card tables, cans on a grocery shelf, speedometers, etc.) and the bottom part is for close vision like reading a book or magazine.

Q. What is a Progressive?

A. A Progressive is the newest technology and is also called the “invisible” bifocal. It can’t be seen by others or by the user. If you could see the progressive, it would look something like this. The top part of the lens focuses far away, the top of the progressive focuses at intermediate distance and, as you look through the lower parts of the progressive, it gets “progressively” stronger (hence the name progressive) to see at closer distances.

Sooner or later, almost everyone suffers from one type of headache or another. But what causes your head to hurt when you have a headache? Your brain tissue itself cannot ache. The truth is that pain cannot occur in most places inside the head at all! Only certain structures can produce the pain we interpret as a headache. But just because the brain does not feel pain itself does not mean that the brain cannot be involved as a cause of the pain. In fact, researchers are convinced that it is.

There are also tissues and structures outside the skull which can produce headaches. The consensus among experts has been that the primary pain structures of the head are extra-cranial (outside the skull), usually the arteries. However, some intra-cranial structures can be the cause of headache pain as well. These include the sinuses, the blood vessels in the meninges (the outer covering of the brain), the dural arteries, the dura mater at the base of the brain, some of the basal cerebral arteries, the three superior cervical (neck) nerves and the cranial nerves (nerves of the head).

Diagnosis of Headaches

Many factors are involved in the diagnosis and treatment of headaches. For example, while it is usually of paramount importance to the patient, pain intensity usually has little diagnostic value. On the other hand, the location of the pain, its manner of onset, its duration, the age of the patient when the headaches begin and its frequency may yield more useful information. Multi-focality (headaches which occur in more than one area or in different areas in subsequent attacks) is usually a relatively good indication of a benign cause while pain which is located in temporal arteries or other extracranial structures can lead to a very specific and, possibly, a very serious diagnosis. For instance, contrary to what is commonly believed, headache pain which is due to a brain tumor is usually not all that severe while the pain from cluster headaches, meningitis and subarachnoid hemorrhages is usually very severe in nature. It is therefore necessary to further differentiate between them (examine characteristics other than just the severity of the pain) in order to arrive at a correct diagnosis.

How fast the pain from a headache develops is usually more informative than the severity of the pain itself: the pain produced by a ruptured aneurysm of a blood vessel peaks instantly and is referred to as a "thunderclap" headache, while the pain of a cluster headache will usually rise to a peak in 3-5 minutes, last for an excruciating 45 minutes and then taper away.

Cluster headaches affect about 1 million Americans (mostly men) annually and are most likely the result of the interaction of the arteries and nerves of the head and/or the release of a chemical transmitter of the brain. Some cluster headache victims (I use the term “victims” intentionally) find relief by rocking in a chair, from vigorous activity or from pacing. These patients may need several months to determine whether or not any given medication is working. The pain of this headache is so severe that patients have been known to pound their heads against walls and even to eventually commit suicide.

Migraines, on the other hand, usually build up over several hours, last from several hours to several days or even weeks and are characteristically relieved by darkness, quiet and sleep. They will also usually decrease in frequency and intensity as the patient grows older. The onset of typical migraine late in life is rare but less rare is the recurrence of migraines which have been in remission. In particular, migraine with aura is well known to recur in the elderly.

Most primary headache disorders have their origins in early or late adolescence or in early adulthood. Headaches which begin later in life almost always warrant more suspicion and further investigation. This is also true of headaches which begin to last longer with subsequent episodes. The possibility of a headache having a serious or dangerous origin is higher for those patients who suddenly begin having headaches than it is for the patient who has suffered from chronic headaches for years.

Tests which are used to investigate headaches may include urinalysis, lumbar puncture, cerebrospinal fluid smears, antinuclear antibody titers, erythrocyte sedimentation rates, temporal artery biopsy, cardilepin antibody titers, serum prolactin levels and neuro-imaging (CAT scans and/or MRI). If your doctor recommends these tests and you do not know what they are or what they will tell him or her, by all means, ASK!

Nearly all illnesses can be the cause of a headache but some illnesses are much better known for producing headaches than are others. Some of the well known diseases which produce headaches are lupus, mononucleosis, thyroid disorder, inflammatory bowel disease, acute (above 120) hypertension and various HIV related disorders. Other headaches can even be the result of medications: oral contraceptives, corticosteroid withdrawal and medications which promote ovulation to name a few. The vast majority of headaches are caused by benign conditions. Others are not. Some indicators of a headache with a more serious origin are:

·        Sudden, severe, first time headaches.

·        A persistent headache of recent onset.

·        Headaches which worsen with subsequent episodes.

·        Headaches which are accompanied by loss of consciousness, altered mental capacity or physical states (numbness, paralysis, slurring of words, etc.)

·        Headaches accompanied by a stiff neck or fever.

·        The onset of headaches in an elderly patient.

·        A headache which occurs in a patient with immuno-suppressed conditions such as HIV or in those who have malignant systemic diseases such as high blood pressure or in patients who have contracted various infections such as meningitis.

·        Any unusual or severe headache which occurs during physical exertion (Rule out sub- arachnoid hemorrhage).

As mentioned earlier, while the severity of the pain may not always be important diagnostically, other information about the pain can be. Examples include a description by the patient of a steady, non-throbbing, "hatband-like" pain which is usually due to stress or tension. This headache pain tends to be constant and chronic. Headaches which occur in the evenings are usually due to anxiety, fatigue or eyestrain.

Ocular pain may also be indicative of an ocular disorder as simple as myopia (near-sightedness), hyperopia (far-sightedness), astigmatism, presbyopia (the need for a bifocal or reading glasses), computer vision syndrome or of a muscle imbalance. It can also be a symptom of an eye disease such as iritis, keratitis, uveitis, scleritis, cellulitis or glaucoma. Pain which is localized at first in the eye can later affect much of the ocular region. It can be severe or even prostrating and can be accompanied by nausea and vomiting.

Migraine headaches and headaches due to hypertension (high blood pressure) usually cause a throbbing pain since they are essentially vascular in nature. While most migraine sufferers can be successfully treated abortively, some must be treated by trying to prevent the headache from occurring in the first place (prophylactically). Generally, prophylactic treatment may be necessary if:

·        Attacks are more frequent than three times in a month.

·        The attacks last for longer than 48 hours.

·        The pain is too severe to be borne or if the patient cannot cope with it.

·        The attacks can't be treated abortively.

·