<P> Though the dioptre is based on the SI - metric system it has not been included in the standard so that there is no international name or abbreviation for this unit of measurement -- within the international system of units , this unit for optical power would need to be specified explicitly as the inverse metre ( m ) . However most languages have borrowed the original name and some national standardization bodies like DIN specify a unit name ( dioptrie , dioptria , etc . ) and derived unit symbol `` dpt '' . </P>
<P> Though the dioptre is based on the SI - metric system it has not been included in the standard so that there is no international name or abbreviation for this unit of measurement -- within the international system of units , this unit for optical power would need to be specified explicitly as the inverse metre ( m ) . However most languages have borrowed the original name and some national standardization bodies like DIN specify a unit name ( dioptrie , dioptria , etc . ) and derived unit symbol `` dpt '' . </P>
si unit of power of a lens is
si unit of power of a lens is
dioptre
dioptre