Question

wgat do you understand by 1 dioptre of power of lence

Answer 1

1 dioptre is the power of lens of focal length 1 m

Answer 2

A dioptre (uk), or diopter (us), is a unit of measurement of the optical power of a lens or curved mirror, which is equal to the reciprocal of the focal lengthmeasured in metres (that is, 1/metres). ... A flat window has an optical power of zero dioptres, and does not converge or diverge light.