Other foods such as spinach kale, broccoli and other dark leafy greens, which contain large amounts of lutein and zeaxanthin, are also emerging as some of the top nutrients for health vision. Eating a variety of colour fruits and dark leafy vegetables, from 5-10 servings daily, will increase the levels of the antioxidants in the diet.
There are also lower levels of Lutein in corn and egg yolks. Corn, oranges and papaya are sources of zeaxanthin. Interestingly, a regular egg supplies less lutein than spinach, but research has shown that the lutein found in the egg yolk is more bioavailable perhaps due to the lipid matrix of the yolk.
Thus vitamin A in carrots alone - while nutritional - has relatively little effect on improving vision. Maintaining a well-balanced health diet, will.
Source : BRIDER, Caroline. « Eggs for Better Sight? », Vision Magazine, September-October 2009, p. 34-36.