Most people and animals naturally have focal distance problems with their eyes. That is, they are either nearsighted or farsighted. One of my dogs is extremely nearsighted, and the other moderately farsighted. And I'm pretty sure one of my cats is nearsighted. Dim indoor lighting has created a lot of nearsighted people that otherwise would have mostly ok focus, but either way it would be a very common problem.
And it's useful to know how well you can see and the normal focusing range of your eyes aren't the same thing. You can have awful eyesight with cloudy lenses, damaged retinas, etc and not need glasses. And you can have amazing eyesight better than 99% of the population and need glasses.
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Most people and animals naturally have focal distance problems with their eyes. That is, they are either nearsighted or farsighted. One of my dogs is extremely nearsighted, and the other moderately farsighted. And I'm pretty sure one of my cats is nearsighted. Dim indoor lighting has created a lot of nearsighted people that otherwise would have mostly ok focus, but either way it would be a very common problem.
And it's useful to know how well you can see and the normal focusing range of your eyes aren't the same thing. You can have awful eyesight with cloudy lenses, damaged retinas, etc and not need glasses. And you can have amazing eyesight better than 99% of the population and need glasses.