Question

the distance between the lens and the retina can't change. speculate as to how we can see objects in focus at many different object distances.

Answer 1

without adjusting the distance between the lense , muscles adjust the thiness of the lense and change focus length of the lense

Answer 2

is that it?

Answer 3

yes

Answer 4

One of the reasons your eyes go bad as you get older is because the material of the lens gets harder to deform, and the muscles that alter the lens geometry get weaker.