If you spend a lot of time at the computer or focusing on any one thing, you sometimes forget to blink and your eyes can get fatigued. Try the 20-20-20 rule: Every 20 minutes, look away about 20 feet in front of you for 20 seconds. This can help reduce eyestrain. 

Eating the following has been shown to help boost your immune system and can prevent illness and long term health issues: Vitamin C-rich foods, like citrus fruit and broccoli, Vitamin E-rich foods, like nuts and whole grains, Garlic, Zinc-rich foods, like beans, turkey, crab, oysters, and beef, Bioflavanoids, which are found in fruits and vegetables, Selenium-rich foods, like chicken, whole grains, tuna, eggs, sunflower seeds, and brown rice, Carotenoid-rich foods, like carrots and yams, Omega-3 fatty acids, found in nuts, salmon, tuna, mackerel, flaxseed oil and hempseed oil.