I understand your concern towards your health care.
Any kind of food that which we take will only help us to maintain health. Like you've been stressing on having fruit or vegetables will increase the sight. Nope they only keep the sight they will not improve the sight unless and untill the vision loss is due to the particular nutrient deficiency. Coming to the food that we should take to keep our eyesight are, all colored fruits will do the job and also the green leafy vegetables will also play a keen role in keeping our eyesight steady. Along with the food you take there are other factors you need to rake care of that are washing your eyes with clean water after you return home from out and wearing sun protective glasses when you go out. Thus small thing will be really effective as yoy follow them.
Take care of your eyes as they are very important sensory organs.