Question: What are the three types of cataracts, and how do they differ?
Answer: Three major types of cataracts -- and there can be combinations of all three of these in the same person's eye -- but the three major classifications would be nuclear, where the central part of the lens is opacified. The other type would be cortical -- where more peripheral regions of the lens become whitened. And the third would be posterior subcapsular cataracts -- where the back surface of the lens develops the major opacity. But as I say, it's not uncommon to have both nuclear and cortical, as well as posterior subcapsular in the same eye.
They have different effects on the vision, and posterior subcapsular most often affects a person's reading vision and gives particular problems with glare. Cortical cataracts can actually be thoroughly extensive and only have a minimal effect on the vision. And nuclear cataract more often affects a person's distance vision, while leaving the reading vision relatively spared.