John Glenn didn't wear them. Neither Madeline Albright nor Toni Morrison chose to cover their eyes with them. So, why did Bob Dylan wear those ultra-cool aviators to the White House when he received the Presidential Medal of Freedom from President Obama?
Sunglasses are an accessory prevalent across all ages, races, and regions of the country. Celebrities often draw sarcastic comments for their tendency to wear their shades indoors.
While most people reach for their dark lenses because of the bright glare of our closest star, other people wear their shades for more reasons than simply sun protection. Sometimes, these reasons cross the threshold into the home, workplace, shopping mall, sports arena, or other indoor space.
• To hide deformities of their eyes or face. This can range from a temporary black eye to something more permanent.
• To disguise their identity. Often, sunglasses hide the shape or color of an individual's eyes. Larger styles can also cover more extensive areas of the face.
• To intimidate others. This goes along with the previous point: Because sunglasses hide an individual's face, they can attempt to express power over others by hiding their emotional vulnerabilities.
• To look stylish or express a sense of "mystery." Any high-end department store will stock multiple styles and colors of sunglasses to help their customers better express their sense of fashion.
• As a status symbol. Many of the expensive sunglasses are emblazoned with recognizable logos or patterns.
But some people have medical reasons -- besides sun protection -- to wear their sunglasses both indoors and out: a condition known as photophobia.
Photophobia: It's Too Bright
Some people have medical and psychiatric conditions in which light causes discomfort in the head or eye. Other people avoid bright lights but don't actually experience any pain. Both of these instances are known as photophobia.
A 2009 study examined 111 adults and 36 children who were seen at a university eye clinic and diagnosed with "photophobia." A cause for this complaint could not be found in most of the children, but the majority of the adults did have a medical reason for their sensitivity to light. These reasons included:
1. Dry eyes
This is likely the most prevalent cause of photophobia. Healthy eyes produce tears to lubricate the cornea, the thin tissue covering the iris and pupillary area of the eye. A lack of lubrication causes changes in the cornea's pain fibers, which may make them sensitive to bright lights. However, this problem is usually easily solved with eye drops and lubricants.
One of the classic symptoms of migraine headaches, photophobia caused by bright lights can affect people with migraines in multiple ways. Bright light or glare, like florescent light or the reflection of sun off of a car's window, triggers between 30 and 60 percent of migraine attacks. Pink-tinted glasses can help this particular cause of photophobia, although this may draw quips about the wearer's tendency to look at their world through rose-colored glasses.
Many migraine sufferers retreat to a dark room, pull the curtains closed, and reach for their sunglasses when they notice their migraine symptoms. Certain Brain PET (positron emission tomography) scans, which measure blood flow and chemical activity in the brain, have shown us that the brain is more excitable during the headache in general, but especially at the time that the test subject complained about sensitivity to light.
This means that the photophobia and photosensitivity experienced during a migraine actually stems from the brain, not the eye. Luckily, many medications are available for these type of migraine symptoms.
3. Brain Injury
Although many visual complaints may be part of the headaches associated with a mild head injury, it is not uncommon for people who have had a concussion to complain about bright lights and problems with glare. The good news: This usually resolves within six months.
4. Emotional Causes
Most eye clinics will see patients with photophobia for which no medical explanation can be found. Some patients actually fake their visual loss. The Neuroophthalmology Unit at Emory University concluded that the patients who wore sunglasses in their waiting room were associated with a 79.4 percent chance of having "non-organic visual loss." That is, these patients' loss of vision was caused by their emotional state -- or they faked their complaints.
Just as a gentleman always removes his hat while inside, sunglasses are rarely justified indoors. In fact, chronic darkness can increase one's sensitivity to light and pain. For those that don't suffer from photophobia, it's time to take off your shades inside -- it's not only polite, it's also good for your eyes. That is, unless you are Bob Dylan.
For more by Richard C. Senelick, M.D., click here.
For more on personal health, click here.
Follow Richard C. Senelick, M.D. on Twitter: www.twitter.com/RichardSenelick