Within the last 18 months the authors have measured, in cases of juvenile cataract seen by them, the axial length of the eye and other parameters. As a control group, children from the authors' squint clinic, with various refractive errors, were examined. With the data thus gathered, correlation and regression analyses were performed, postoperative refraction values were calculated, and eye growth in phakic eyes was compared with that in aphakic eyes. Regression formulas were established which enabled the authors to calculate eye length at a given age, to determine the postoperative refraction of their juvenile cataract patients with great accuracy, and, so far, to prove that there is no significant difference between phakic and aphakic eyes as regards growth.