Methods of increased contact lens rotation

A contact lens for use in preventing or slowing the development or progression of myopia, the lens including an optic zone and a peripheral zone surrounding the optic zone, the optic zone comprising:

• a central region, the central region having a first optical axis and a curvature providing a base power and centred on a centre of curvature that is on the first optical axis;
• and
• an annular region, wherein the annular region circumferentially surrounds the central region, and wherein the annular region comprises a treatment zone having a characteristic that reduces the contrast of an image of an object that is formed by light passing through the central region and the treatment zone compared to an image of an object that would be formed by light passing through only the central region, the treatment zone comprising an add-power region having a curvature providing an add-power of 0.5 D or more, wherein the characteristic that causes the contrast reduction varies with meridian around the annular region, and
• wherein the peripheral zone has a constant thickness profile in every meridian or a variation in thickness configured to promote rotation of the lens.