I have three tips for you:
First two are related to vitamin A, which is most important for your eyes.
1. carotene oil which has very big amount of this vitamin. If you will make your food only with this oil, you will have daily required amount of vitamin A.
2. Carrots carrots and one more time carrots
3. Regular eye exams. They are expensive sometimes, so check for coupons! I wrote informational hub about eye exam coupons if someone will be interested in this kind of activity. BTW - did you know that eye exam will show your sugar level and diabetic alarm?