Q: We have heard of skin getting sunburned, but can our eyes also get sunburned?
A: Yes. Prolonged exposure to sunlight causes damage to all components of the eyes. First, the eyelids, having a very thin skin layer and containing many fragile tissues, may become cancerous (eyelid and intra-ocular melanoma) and lose their blinking and secretory functions. Also, the cornea may become inflamed (photokeratitis) and cause pain with vision change. The intra-ocular lenses will become cloudy with time (cataracts) and cause reduced vision. The fragile neural layer or retina, if intensively injured, may cause permanent vision loss (maculopathy).
Q: What exactly are sunlight UV rays?
A: Ultra-violet rays are components of solar radiation, but may also be present in artificial sources like welding machines, tanning beds and lasers. There are three types of UV radiation: UV-C is absorbed by the atmosphere ozone layer and does not cause us direct harm, but UV-A and UV-B adversely change the molecular structure and the function of the eyes.
Q: Do darker tinted sunglasses mean better sun protection?
A: No, darker sunglasses without proper UV blocking capacity actually are more harmful because they let more unfiltered UV rays enter through the more widely opened pupils (induced in the darkened environment created behind the heavy tinted lenses).
Q: What do we look for in sunglasses for protection against UV rays?
A: Not all sunglasses offer adequate protection. I recommend sunglasses that have the following:
- The CE Mark and British Standard (BS EN 1836:2005), a UV 400 label, or a statement that the sunglasses offer 100% UV protection.
- Sufficient size to shield the eyes, eyelids and surrounding areas; wrap-around styles with a close-fit, and UV-protective side shields.
- Durability and impact resistance.
- Preferably polarized lenses to eliminate glare when driving or when out in the snow or on water; continuing glare may cause fatigue, headaches, and even migraines.
Q: Recently, there is a lot of discussion about blue light. How does it affect us?
A: Blue light is a natural component of the visible light, but is much more intense when emitted from electronic devices, LED or fluorescent light bulbs. Though it does not usually damage the eye structure, it does affect our circadian rhythm by suppressing the production of melatonin (relatively more than other light colors) which regulates our sleep, eating and other activities. Thus, blurred vision and lack of focus resulting from sleep deprivation and tiredness are indirect consequences of excessive and continuous exposure to blue light. Blue-blocking lenses offer protection against blue rays from electronic screens.