A pair of spectacles has an individual lense, one for each eye.
Depends on the type of defect of the eye
No.
Extremely critical.
to magnify it
A lens is a device that changes the direction of light.
The objective lenses are the optical element that gathers light from the 'object' being observed and they focus the light rays to produce a real image.
It is possible to do so - you will need to contact your optician.
They enlarge and put into focus the object on the slide.
replace the natural lens that is removed during cataract surgery
No you do not. I started with daily disposables when I was 11years old.
replace the natural lens that is removed during cataract surgery
It is a lense that is curved so that you can have a wider shot than normal