Question

Is focal length of eye lens fixed?,

Answer 1

yes it is with the help of concave ,convex and biconvex lenses for each of the following defects: Nearsightedness , Farsightedness and Presbyopia.

Answer 2

HELLO DEAR FRIEND

$\large\underline{thickness \: of \: lens \: is \: not \: fixed}$

THICKNESS OF THE LENS DEPENDS UPON THE FOCAL LENGTH OF EYE

AND THICKNESS OF THE LENS IS CONTROLLED BY THE ACTION OF CILIARY MUSCLES WHICH IS CALLED THE POWER OF ACCOMMODATION .

HOPE IT HELPS YOU DEAR FRIEND THANKS