Macular degeneration is a type of chronic, progressive disease that gradually destroys sharp central vision. It occurs due to a deterioration of the macula, a tiny spot in the central portion of your retina that is comprised of millions of light-sensing cells that all together help to produce your central vision. Over time, as you age these photoreceptors become thin, worn, or damaged and thus can cause objects in front of you to appear blurry or lack detail. Macular degeneration does not affect your peripheral vision.