This is the eye getting old!!
With age the lens of the eye loses it’s flexibility and becomes stiff. It is unable to change it’s shape which is an important factor in focusing. So when you read you find that you have to move the print further away to a point where the lens can focus ie your arms become too short.
This is alleviated with reading glasses.
It is possible to have the natural lens removed and a special ‘accomodating lens’ inserted. This is a rapidly developing area within ophthalmology. See section on cataract.