In myopia or nearsightedness, the eyeball is “longer” than normal, so the light that comes in does not directly focus on the retina – the layer of tissue that is the inner lining of the eye-- but in front of it.
As a result, close objects are seen in focus, but far objects appear out of focus or blurry.
The most common symptom is "blurred" vision.
Causes could be genetic and not necessarily hereditary.
Can I detect myopia in my son if he’s still a baby?
Yes, with specific ophthalmologic studies.