What are recommended food items that can sharpen my eyesight?

Food to preserve: Foods such as fish (salmon, tuna) been shown to delay eye disease. Areds formula vitamins have been shown to delay eye disease in age related macular degeneration. Centrum vitamins have been shown to slow down cataract formation. I am not aware of any studies that improves vision.

Nutrition: Unless you have a specific deficiency a regular normal healthy diet would suffice. If a deficiency is present then the appropriate supplements would be required.