The fudged formula for intraocular lens power calculations.

The formula presented is a modification of Colenbrander's formula. The formula yields a 0.70 diopter stronger power emmetropizing lens for a 23.0 mm eye. It also fudges the axial length by subtracting 0.1 mm for each 1.0 mm longer than 23.0 mm, and by adding 0.1 mm for each 1.0 mm shorter than 23.0 mm. Axial length was measured using immersion A-scan technique. In our prospectively tested group, the adjusted formula predicted implant power within +/- 1.00 diopter in 95% of eyes.