[Evaluation of the refraction factor using the theoretical formula for calculating the intraocular lens power]

The refraction factor was evaluated by using the theoretical formula for intraocular lens power calculation. This evaluation was made for several combinations of lens position, postoperative refraction, corneal power, axial length and lens design. The calculated values range from 1.19 to 1.51. Refraction factor was found to increase with posterior position of the lens, corneal power and algebraic increase of postoperative refraction. Position of the lens is the most important factor. The following values can be used practically: 1.25 for anterior chamber lenses and meniscal lenses; 1.33 for posterior chamber plano-convex lenses; 1.50 for posterior chamber biconvex lenses.