The second main reason seem ophthalmologist is any change in the eye. Firstly, it refers to the pain. Any eye pain, especially when moving the eyeballs, as well as redness and inflammation necessarily require a doctor's advice, especially in the case if you have recently had injury to the eyes or head. Eye pain may be caused by such diseases as retinal detachment, which can lead to complete loss of vision, so do not waste your time.
Dry eyes, burning sensation of "sand" in the eyes often occur when the voltage of the eye, such as long working at the computer. But if these symptoms occur regularly, you should consult your doctor - you may have a problem with the optic nerve or muscle, and can be, the situation is even more serious.
Of course, if you feel that you have become less visible, you should immediately go to the doctor. Nearsightedness or farsightedness is suffering a lot of people, and nothing particularly wrong with that, but maybe you can still restore sight to the unit using the procedures without surgery and without wearing glasses or lenses. So do not waste your time.
Floating before the eyes of black flies, light flashes and green spots, too, do not bode well. From time to time they appear at all, but it's best to consult with an ophthalmologist to rule out the possibility of a serious illness.
In fact, many unpleasant sensations in the eyes, blurred vision and black spots may be a sign of other diseases not related to the eyes. For example, with diseases of the central nervous system. So ignore them just not worth it.