The eye needs light in order to work, but too much bright sunlight (as we have here in the UAE) may be associated with damage to the retina (age related macular degeneration). It is sensible therefore always to wear a hat/cap with a brim or dark glasses when out in bright light.
The most important environmental factor associated with eye disease is smoking – smoking is bad for retinas. Yet another reason to give up the habit!
Diet is also important – dark green leafy vegetables (spinach, kale, and broccoli) contain micronutrients that are important for the health of the retina. A balanced diet is sensible for many reasons.
Vitamin and mineral supplements in the form of pills or powders have a limited role in protecting the eyes in someone eating a balanced diet. There are some forms of age related macular degeneration that can be helped by these pills – consult your doctor if in doubt. Remember that too many supplements can also be harmful so always only take the recommended dosage.