Question

Which lens is used in spectacles ?

Answer 1

In myopia the lens used is concave In hypermetropia the lens used is canvex In presbyopia the lens used is bifocal lens which contains both concave and convex and concave lens is at the upper part and the convex lens it is at the lower part the concave lens is used to see the fall of objects and the convex lens is used to see the nearby objects In astigmatism the lens used cylindrical lens Now i hope it helps u

Answer 2

Heya !!!

Lens that are used in spectacles are used according to the need.
If the person is suffering from Myopia, i. e. He is not able to see the objects far away clearly. Then he needs concave lens.

If the person is suffering from Hypermetropia, then he/she need to use convex lens.  
At old age, sometimes.. the old people need to use bifocal lens, which have both convex and concave lenses. 

Hope You Got It