To develop and function properly adequate lighting is very important for our eyes. Children who spend some time outdoors on a regular basis have reduced rates of certain eye conditions, for example short-sightedness.
So, what happens when our eyes get too much sunshine?
The main reason our eyes and skin are damaged from sun exposure is ultra-violet radiation, generally referred to as UV. UV is emitted from the sun in rays as visible light is but we can’t see it (because our retina can’t detect rays of that “wavelength”). A number of changes, in the short and long term, can occur to our eyes when they have too much UV exposure.
Short term effects (that can continue if exposure isn’t reduced) can include painful, red, watery eyes and feeling like there is sand in the eye. In extreme cases photokeratitis (‘light’ induced inflammation of the cornea) occurs. Depending on the means of acquisition, photokeratitis can be called welders flash or snow blindness.
In the long term over exposure to UV is linked to earlier cataract formation, tumours of the eyelid and pterygium development. There may also be a link between sun damage and macula degeneration – research is continuing in this area. It is currently thought that sun related damage to the macula may be related to high end visible light, i.e. blue/purple light (the front of the eye absorbs UV meaning it doesn’t get through to the retina).
It has been well established that limiting the amount of damaging UV rays that get to our eyes improves to ocular health. The most effective way of doing this is with a pair of sunglasses. Hats are also an excellent mode of UV protection; they shield parts of our face as well as our eyes but don’t adequately protect our eyes from reflected light. Another sun smart step to take is avoiding extended exposure to direct sunlight between 10 am and 2 pm.