Slight degrees can cause headaches, fatigue and poor schoolwork.
More serious degrees produce blurred vision at all distances.
It is the loss or lack of central vision in one eye or the inability of the eyes to focus together. The inability to see things clearly that are up close. Many children will pass vision tests that measure distance but have difficulty with reading or close work. The inability to see things clearly at a distance. One or both eyes turn in, out, up or down, independent of the other eye.