Originally appeared in
EARTH STAR MAGAZINE February/March 2005
Rosemary Gaddum Gordon, D.B.O., M.A.
Dazzle and glare are often problems for those of us who spend long hours indoors. We leave the office, it’s dark and on the drive home the headlights feel uncomfortably bright, or in the summertime, we go from the relative shade of a building into the sunshine and it can feel overwhelming. However, natural unfiltered sunlight is necessary for our general health as well as for our eye health. Humans evolved in sunlight.
There has been much discussion over the past decade about the harmful effects of sunlight on the eyes. We’ve been told to protect our eyes against the light all the time. It is sadly true that particularly here in the Northeast, the ozone, which is the earth’s natural protective layer, has been eroded. This means that we are more exposed to the harmful rays than we used to be. However, our eyes love light. Without light they don’t see.
There’s a story about an ophthalmologist who went spelunking and found some fish in an underground lake. He found that he could pick them up and noticed that the fish had anatomically correct eyes, but they could not see. He took a couple of them back to his pond. About six months later an ophthalmologist friend was visiting and they went out to see the fish. As the doctor reached down to show his friend how he could pick them up, the fish swam swiftly away. During the six months in the sunlight the fish had developed sight.
Bright indoor lighting can be used as a partial substitute, but outdoor light is much brighter than even a well-lit room. One of the things that happens when we spend hours indoors is that our pupils, (the black hole in the eye through which the light passes), no longer become small enough in response to bright light. This can result in the eyes receiving much more light when it’s bright, than we are either used to or comfortable with. The eyes may water excessively and even feel painful. We will tend to squint or close one eye as a way to shield them and stop so much light from entering. A usual response is to go out and get sunglasses. These can actually make matters worse. The iris, a sphincter muscle, which like most muscles becomes weaker if we don’t use it, controls the size of the pupil. When we wear dark glasses the brightness of the light is diminished so the iris is not stimulated to contract as much. If we get in the habit of wearing sun glasses much of the time the muscle is not exercised and loses some of its capability. So, if we lose our shades we’re in worse trouble than we were to begin with.
Sunlight is essential for our health but we mustn’t get too much of the wrong kind. So we need to find a middle way between too much and too little. One approach is to spend about 20 minutes everyday outside without dark glasses, and if possible without any glasses on at all. If your eye doctor specifically tells you not to do this, then, at least get some light on your skin. (Skin cancer is more prevalent among office workers than among people who work outdoors. It has to do with burning.) If the weather is overcast, it’s still worth going outside because it will be brighter outside than in.
There are some considerations to keep in mind as you find your Middle Way. When the sun is lower in the sky there is more atmosphere through which the light rays travel, so fewer of them reach us. Consequently, early and late on a summer day is safest, as is the wintertime. However, when there is snow on the ground there is a high degree of reflected light, so on bright, sunny, snowy days we need to be more conservative. As you use the technique described below and begin to wean yourself from your frequent sunglass-wearing, remember it is muscles you are working with. At first they may be slow to respond, so if you walk outside and the light feels too bright take a few deep breaths, blink and look at the shadows and the darker, non-reflecting surfaces like trees and bushes, while your eyes adapt.
The simple technique you can use to help your eyes to be more adaptive to changes in light is called Sunning.
Stand with your eyes closed in the sunshine or in front of a 150 watt flood bulb. Gently swing your body from side to side, with a slight turn at each end. Let your closed eyes pass through the warmth and light into a little shade at the ends. Find a rhythm that feels comfortable and continue for 5 minutes or more, being aware of the comfort of the warmth (don’t do it where it’s hot) and the restfulness of the movement. It’s supposed to feel good so that you relax. This allows your pupils to practice constricting and dilating. Avoid doing this when the sun is high because you don’t want to strain your neck. Afterwards palm your eyes: close and cover them with you hands letting the warmth soak in even more deeply.
If you prefer to sit when you sun, just rotate your head gently from shade through brightness to shade again. Making sure you are breathing fully.
Remember, if you have any medical reason for being extra careful in sunshine, the light bulb is a wonderful substitute, as it is for dreary, gray days.
Avoid buying sunglasses that are very dark. You want your pupil to be active. And, be sure to get the ones that block all UV light, because your pupil will be more dilated behind the lenses, allowing in more harmful rays than if you were not wearing any sunglasses at all.