Bilberries is an excellent suggestion; can be taken as jam, as tea,extract, dried as a snack etc. Very tasteful; my kids favorite, they grow wild around here.
I would suggest buying it as a powder; can be mixed with anything or taken straight from the spoonful.
ps it stains easily!
Other herbal / supplemental suggestions;
http://www.herbal-supplements-guide.com/how-to-improve-eyesight-naturally.html
How to Improve Eyesight Naturally With Therapeutic Herbs
Bilberry Extract - Bilberry contains anthocyanosides that may decrease the rate of macular degeneration and prevent other retinal conditions from occurring. Bilberry protects veins and arteries in the eye, and helps with night vision.
Aspalathus - A powerful herb native to South Africa, aspalathus or rooibos contains antioxidants similar to bilberry and can promote eye health as well as improve immune function.
Mahonia Grape Extract - Grape seed extract protects the eyes from UV and sun damage, as well as strengthen capillaries in the retina. Mahonia slows eye aging, and helps with overall eye health.
How to Improve Eyesight Naturally With Other Nutrients
Vitamin E - a powerful antioxidant that has been shown to slow the onset of macular degeneration and protect the retina.
Vitamin C - another antioxidant that works with Vitamin E to protect tissues and improve eye health.
Zinc - an essential mineral required by all cells in the body, zinc helps strengthen the cells of the eye.
Fish oil - contains powerful compounds that can prevent macular degeneration and other eye problems.
http://www.herbs2000.com/articles/triphala.htm
Triphala in correcting eye disorders
It may be noted that the use of triphala is also widespread for healing ophthalmic ailments. And this also includes the treatment of eye ailments like progressive myopia, conjunctivitis, cataracts as well as the initial stages of glaucoma (an eye disease that damages the optic nerves and impairs vision. At times it may also lead to blindness).
Before wrapping up the subject, it needs to be mentioned that the use of triphala, a combination of three herbal fruits, is the most widespread combine used in Ayurvedic medications since ages. If one goes through the Ayurvedic literature, he or she will find that the use of triphala fills volumes of pages. In addition to being an all-purpose stimulant or tonic, triphala is a mild laxative, serves as a nourishing substance for the eye, skin and liver and is also a common detoxifying agent that cleanses the body of all toxins.