1mm change in the axial length of the eyeball produces a change in refractive index by: March 2005

Ans. C: 3D 1mm change in the axial length of the eyeball produces a change in refractive index by 3 D. Elongation produces myopia and shoening causes hypermetropia. 1 mm change in the radius of curvature of the cornea produces a 6 D refractive change. Steeper (more curved) corneas produce myopia and flatter corneas hypermetropia.