Rotation of spherical nonprism and prism-ballast hydrogel contact lenses on toric corneas

Six subjects were fitted binocularly with both nonprism and prism-ballast spherical HydrocurveTM contact lenses to evaluate lens rotation on toric corneas. The 1/2 delta and the 1 delta lenses rotated significantly less than the equivalent nonprism lenses. For 11 of 12 eyes, 1/2 delta was sufficient to stabilize the lens.