A color conversion device generates color data in a second color gamut based on first converted color data and input color data, which are obtained from input color data in a first color gamut, and outputs the color data in the second color gamut. The broken magnetic strips have a different magnetic characteristic as compared to when they are intact and this can be sensed with a Hall effect or other sensor. An embodiment of the lens curing system includes an apparatus for preparing an eyeglass lens. The form has a stepped structure, with the upper portion of the form having a smaller circumference than the lower portion and a transition between the upper and lower portions forming the step.