If you have ever had to drive into the sunrise on your way in to work in the morning or into the sunset on your way home for that matter, you are no doubt familiar with glare. It’s a term we all use, but few spend any time thinking about what it really means, and it is actually much more complicated than people realize. Just what is glare? How does it happen? Is there any way to avoid it? At Georgia Eye Physicians and Surgeons we are concerned with all aspects of eye and vision care, and have found that the answers to these questions can actually help “shed some light” on cataracts, one of the leading causes of vision loss.
In simple terms, we can see the world around us because light from the environment enters the eyes and is focused, by a clear, flexible lens, onto the light sensitive photo-receptive cells that line the retina at the back of the eye chamber. Different colors of light have slightly different wavelengths, and the photo-receptive cells can distinguish between those wavelengths, allowing us to see a contrast between an object and its surroundings. Glare is a problem because it interferes with our ability to recognize those contrasts, blurring the outlines of objects and potentially making the entire visual field appear to be a single, monochromatic haze. When there is a strong light source within the visual field, the pupils of the eyes naturally constrict, protecting the interior of the eye by allowing less light inside. However, this has the side effect of making everything else in the visual field much darker and less distinct. The eye has to work much harder to distinguish between objects and their surroundings, resulting in increasing levels of eye fatigue. In severe cases, this exaggerated contrast can cause pain, discomfort, and an instinctive desire to look away from the offending light source.
Because glare is not caused by the brightness of a light source, per se, but rather by the difference between the brightness of a light source and the brightness of its surroundings, basic sunglasses that reduce all light levels by the same amount can do little to alleviate it. However, polarized sunglasses equipped with a special anti-glare coating can block the more intense light rays without interfering with less intense background sources, reducing glare. Unfortunately, the cause of glare is not always external. As the eye grows older, its ability to tolerate intense light tends to decrease which causes the effects of glare to become worse. Refractive errors like astigmatism, caused by imperfections in the shape of the cornea, can also prevent light from focusing cleanly on the retina, increasing the possibility for glare or halos. Both of these conditions can usually be corrected by using simple prescription eye glasses and contact lenses, or in some cases with LASIK surgery. Finally cataracts, or cloudy imperfections in the lens itself, can scatter light as it enters the eye, making glare far worse than it would be normally. Cataracts often cannot be detected during a routine vision exam, and may require a comprehensive medical eye examination in order to properly diagnose. In most cases, cataract surgery will be able to replace the damaged lens with an artificial intraocular lens implant, significantly improving vision under all conditions.
The eyes are sensitive and complicated organs, and there are many different conditions that can affect them, but eye specialists Dr. William Segal and Dr. Marc Lay are dedicated to understanding and treating all of them. If you have concerns about your vision, or would like to schedule an appointment for a routine vision exam or comprehensive medical eye exam, please contact Georgia Eye Physicians and Surgeons today to make an appointment. Be sure to follow us on Facebook, Twitter, and Google+ for more tips for healthy eyes.