Power of a lens is 1 dioptre if its focal length is 1 metre.
1 dioptre is the SI unit of power of Lens whose focal length is 1m . It is denoted by the letter D.
1 dioptre is the S I unit of power of lens
S.I unit of lens.

1 dioptre is the power of lens whose focal length is 1 metre..
The lens which have f=100cm so the power of lens is 1 dioper
1 dioptre is the power of the lens whose focal length is in meters