It causes blurring of vision for close work. In late thirties or early forties there is again the onset of hypermetropia.
Symptoms develop in the form of eyestrain.
Children below six years are treated only if the refractive error is high. Those between 6-16 years require constant correction and yearly checkups due to change in power with the growth of the eyeball. Myopia or short sight causes blurring of vision on viewing distant objects. It may be due to genetic developmental defect or even physical debility. It's onset is rare after 25 years.