Vision Information - Light Sensitivity
When a light source affects our ability to see clearly, we refer to it as glare. Glare can be categorized into discomfort glare and disability glare.
When a light source is too strong for our eyes, we experience discomfort glare. Usually this causes us to screw up or shade our eyes and may even cause us to close our eyes.
An example of discomfort glare is leaving a dark room and moving into bright sunlight. We feel discomfort while our eyes adjust to the new light source but, after a few seconds, we're able to see clearly and comfortably again.
Disability glare can be caused by eye diseases and reduce our visual performance. With such diseases our eyes can be affected by ordinary light sources and levels of light.
The most common example of an eye disease affecting vision is a cataract. The eye lens in patients with cataracts is not as clear as it should be and incoming light is scattered rather than following its usual direct path to the retina at the back of the eye. Vision is blurred, and coping with bright light becomes difficult. Cataract patients usually have a lot of trouble with glare.
Causes of glare
Ocular albinism, a congenital disease in which the eye lacks pigment, causes glare. Various eye diseases like cataracts, macular degeneration and uveitis can cause glare. Patients with conjunctivitis and corneal problems also suffer with glare. In meningitis, light can actually become painful.
Light sensitivity problems should always be checked out by an optometrist as it may be a sign of a more dangerous underlying condition.
Drugs taken for other medical conditions also can cause light sensitivity, such as the antibiotic, tetracycline, and digitalis, a drug used for heart disorders.
Treatment for light sensitivity will always depend on the cause. If, for example, glare is caused by a cataract then treatment of the cataract will solve the problem.
But not all light sensitivity caused by eye disorders can be treated. The light sensitivity caused by macular degeneration is a case in point. Other treatments may be needed to give patients comfort when dealing with bright light.
Other methods to cope with Light Sensitivity
The easiest way to cope with glare is to limit the light coming into the eye. Shading the eyes with the hand or a wide-brimmed hat can reduce glare with little expense.
If you're able to wear tinted lenses, glare can be substantially reduced.
If you wear sunglasses, ensure they have a UV filter to protect your eyes from the harmful ultra-violet rays of the sun.
Light activated sunglasses can be useful as they get darker in brighter conditions.
Sunglasses with wrap-around shades have built in sides to stop light entering at the side or above the eyes. They can be worn over regular glasses and come in a variety of tints.
A consultation with a low vision specialist can help in coping with glare - for interior and exterior light levels. Many people with a sight problem may need a task light for reading and a specialist may be helpful in choosing one that is appropriate.
Light Sensitivity in disease-free people
One needn't suffer from an eye disorder to experience light sensitivity. But it remains important at the outset to have your eyes checked by an optometrist or ophthalmologist to rule out a serious underlying cause.
Unfortunately some people are light sensitive without a physical cause. Light sensitivity has a scale and some people are simply more sensitive to light than others. Aging also increases sensitivity to light.
Migraine sufferers tend to be more sensitive to light during a migraine headache and to a lesser degree at other times. These sufferers may benefit from special precision tinted lenses.
Light sensitivity can become quite intense and sunglasses and hats will be an obvious help. Wearing the correct sunglasses will not harm the eyes or make them lazy.
Colored lenses, with particular tints, are often used to help people with light sensitivity.
Tint colors range from yellow, to reds and blues. An optometrist can help to choose the tint most suitable for a particular condition's needs. An instrument known as the MRC Intuitive Colorimeter is sometimes used to determine the color or filter.