Darwin himself confessed that it was "absurd" to propose that the human eye evolved through spontaneous mutation and natural selection. How much do we really understand about our eyes? Would you be suprised to learn that even people would 20/20 vision may still have a need for glasses? Unfortunately, there is no such thing as a perfect anything and that includes the eye. People often equate 20/20 vision with perfect eyes, when in reality there are multiple silent diseases that can only be diagnosed with a comprehensive eye exam. A patient may maintain 20/20 and lose peripheral vision or paracentral vision or even all vision in later stages. Thankfully, with early intervention, some of these problems can be mitigated.
For a fun clip to help better understand how our eyes function (or misfunction, if you will) check out the video below from the National Eye Institute.