Can you see clearly close up, but not far away? If so, you could be nearsighted. Nearsightedness, or myopia, happens when light focuses in front of the retina, as opposed to on the retina, usually because the eye is elongated. It’s often passed on genetically, and usually detected between the ages of 8 and 12. Nearsightedness usually worsens during adolescence, and stabilizes in early adulthood.