MASS AND CENTROID OF RIGID LENSES

By subdividing a lens design into simpler units it is possible to eval uate its mass and locate its centre of mass (the centroid). The consti tuent subcomponents form plane sections of the sphere, or, in the case of aspheric lenses, sections of a conicoid. The theory of lens analys is in terms of the conicoidal (and spherical) frustrum is discussed an d a BASIC computer program is presented to perform the calculations fo r spherical multicurve contact lenses.