Well, I believe that you are pretty right now. Because it is true that eye drops could not eliminate the problem once and for all, and your eyes appear to get dry again and again. Anyway, vitamin A could of course lead to better eye health, maybe it would fix the dry eyes. Also, you still need other vitamins and nutritions, and better yet, try to form better living habits and pay more attention to your eyes.
Well, yes, vitamin a can help you to treat dry eyes. So just be careful about the intake of vitamin a. if you suffer from the vitamin a deficiency, it will be bad for dry eyes. For dry eyes, if you do not have the necessary balance of these three layers in your eyes, or if your eyes do not make enough tears to coat the eye, you may have it. So for your situation, you can take some foods which are rich in vitamins such as the fishes and some other vegetables. Also, you should know that if you have dry eyes, scratchiness, itching and burning on the surface of your eyes may occur in your eyes. so it can be dangerous.
If you got dry eyes, you might feel eyes red, gritty, pain, a sensation of foreign body, itching and a little sensitive to light. Then what caused dry eyes? Tears are very important in eyes. They are produced by glands in the upper eye lids. Most components of tears are water, oil and mucus. Each of these components has different functions. Water could moisturize our eyes. Oil could lubricate eyes so that it won't be uncomfortable and gritty if we turn eyeball or make any movements. Mucus could help tears spread evenly on eyeballs. Each component plays important role. Taking some vitamin A is good for mucin layer of tears. Good food resources for vitamin A include carrots, yams, sweat potatoes and so on. Yet what exactly caused your dry eyes needs more investigation. I still suggest you to get help from oculists.