I suggest you to go to see your doctor. Or if the pain was caused by your overworking, you can go to see your doctor to buy some anti-inflammatoryand anti-oxidation patches, which can release your pain and protect your corneas. They are effective to cure itchy, sore and swelling eyes. And vitamin has a close relation with eye disease and poor sight. People who use their eyes too much need much necessarily vitamin and minerals. It is important to supply vitamin needed by the eyes to protect eyes, prevent eye injuries and raise eyesight. In order to reduce eyestrain, we should balance diet and nutrition. And we should eat plenty of fruits, leafy vegetables, coarse cereals, potato and beans which are high in protein, vitamin and cellulose.