While I've been fortunate to have had good health, my eyes have always been a bit of a problem. As a child, I was quite near-sighted (ending up around -7 diopters of myopia- i.e. is that an "E"? ;-) but this was correctable via glasses and (later on) contacts. Fortunately, I did not have much astigmatism (which is harder to correct, especially in contacts) and my vision was fairly stable from ~20 to age 40. One "nice" thing about being so Myopic is that without glasses/contacts, I can focus very close. I did consider having Lasik, but the combination of high Myopia and thin Cornea meant I was a borderline case. Around age 40, it started becoming more difficult to focus (when wearing correction) at close distances, especially in low light. This is a very common condition called Presbyopia which is due to your crystalline lens becoming less elastic. In 2010 (age 46), I noticed that my right eye had more difficulty seeing things. I had been told it had a "small" cataract, but these can often exist for years with no impairment of vision. Unfortunately, I had a Posterior Subcapsular Cataract - these "grow" faster, are more prevalent in younger people, and cause greater visual degradation due to the location at the rear of the visual axis. Because of the cloudiness, you are no longer able to correct to 20-20. An analogy would be a blown window that now has a permanent haze. I'm a bit of a photographer who really analyzes camera gear (and shoots through the viewfinder using my right eye - bummer!) ... so I'm aware that image quality encompasses more than just seeing "20-20" on the eye chart.