Why are the largest visible-light telescopes in the world made with mirrors rather than lenses?

Light distorts through lenses more then it does on mirrors. Images are harder to make out and mirrors are cheaper then all the glass they need for the lenses especially because of contorting the lenses.

Hope this helps!

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)