A lens meter having a simple configuration, which is capable of precisely
measuring optical characteristics such as refractive power distribution
in a wide range of a subject lens to be measured at a time. The lens
meter has a projection unit which projects a measurement light bundle, a
projection lens which projects the measurement light bundle from the
projection unit onto the subject lens placed on an optical axis of the
projection lens, a diaphragm having an aperture disposed between the
projection unit and the projection lens, and a two-dimensional
photodetector which photo-receives the measurement light bundle passed
through the subject lens after passed through the aperture of the
diaphragm and the projection lens, and wherein the projection unit forms
a target pattern, and the aperture of the diaphragm is disposed at a
front focal point of the projection lens.