In us, our eyes. In man made items they are used in such things as cameras, phones or other optical equipment
to magnify it
Depends on the type of defect of the eye
Lenses should only be used after being prescribed by an optician or optermist! netlenses.com.au
No.
yes, they are. Contact lens back surface isn't important for the dioptric power; the frontal sourface replaces the frontal sourface of the cornea. So the light angle of incidence is modified and the light focalize correctly on the retina.
Extremely critical.
concave lense is a piece of smooth glass that is thick from the edges and thin from centre and is used to diverge light rays.
A lens is a device that changes the direction of light.
It is possible to do so - you will need to contact your optician.
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.
They enlarge and put into focus the object on the slide.
replace the natural lens that is removed during cataract surgery