Dry eyes are usually caused by the shortage of tears which help to make the surface of your eyes smooth and clear, also protect your eyes from infection. Your tears are more than water .It contains fatty oils, proteins and electrolytes. You will have poor tear quality if there are problems with any of the three ingredients and then can cause dry eyes symptoms. For example , the lack of oil in tears are unable to help prevent evaporation before the corneas have been fed and lubricated.Also your eyes will become dry if you don't produce enough tears to keep your corneas properly fed and protected.
If there are some signs of health problems, we should pay attention and do something about it. Dry eyes are usually resulted from a lack of sleep and relaxation of your eyes , maybe constant exposure to computer screen or too much reading. Anyway, you should watch less TV and play less PC, also try to take exercises and take in vitamins and fruits and vegetables.