A rigid lens shows two curves on the convex surface measured with radiuscope, but shows one power on the lensometer. What type of lens is this?

The scenario describes a rigid lens that exhibits two different curves on its convex surface, indicating that there are two different radii measured with a radiuscope. This configuration suggests that the lens is not symmetrical and has an irregular surface profile. However, when the lens is measured with a lensometer, it shows only one power.

A warped lens typically displays this characteristic because the two curvatures can reflect deformation from the original shape due to various factors, such as improper fitting, material stress, or mishandling. The presence of multiple curves on the convex surface often leads to inconsistencies in the lens's optical performance, but when measured as a whole in a lensometer, it presents a single effective power due to the averaging of the curvatures across a given light path.

In contrast, other lens types like normal, aspheric, or variable power lenses portray distinct properties that do not align with the description—normal lenses show a single curvature and power, aspheric lenses have a gradual change in curvature without multiple distinct curves, and variable power lenses inherently demonstrate a gradient of power changes over the lens surface.

Thus, the characteristics of a warped lens, particularly showing two curves but only one effective power on a lensometer, indicate physical distortion rather than an