There is no standard answer. If you look at I-Caps Lutein & Zeanthine formula (one of my favorite eye supplements) you would see some basics like
beta carotene anywhere from 5000 to 10,000 IU a day
Vit E 150 to 400 IU a day
Vit C 500 to 1000 mg a day
Zinc 20 - 60 mg a day
Selenium 40 - 60
Copper to prevent iron anemia due to taking zinc
Lutein 10 - 20 mg a day
Billberry - is an herbal ideal - and not scientifically backed - so take it if you want to no hard science behind it.
Remember that beta carotene supplements have been shown to increase lung cancer rates in smokers or previous smokers so if you are in that catagory I cannot recommend beta carotene. Make sure the vitamins you take are ok with your other medications and ok'd by your medical doctor.
Actually, in the above list I meant Vitamin E and not D.
High does vitamin supplementation (i.e AREDS) is very controversial for eye dsorders. The original research was flawed but got positive press for god knows what reason. The dangers of high dose vitamins outweigh any potential visual benefit in my opinion. If you can, read the original research articles on this.
Thanks a lot for the responses, guys.
In regards to beta carotene, I just take Vitamin A, to which beta carotene is a precursor, I believe. Any idea on doses for Vitamin A? Are there any benefits to taking beta carotene over Vitamin A beyond the lesser risk of toxicity?
I actually use the Bausch & Lomb AREDS Lutein formula, though I only take one every other day rather than one twice a day because I already get some its ingredients in a multivitamin.
What about Omega 3 oils? And I believe flaxseed was mentioned in another thread.