The authors aimed to evaluate the effect of age at primary intraocular lens (IOL) implantation on the rate of refractive growth during childhood. This was a retrospective study of 296 eyes of 219 patients. Forty-six met inclusion criteria; 28 unilateral and 18 bilateral cataracts. Patients were aged one to 72 months at time of surgery (mean 35 months). Follow-up was a mean of 108.1 ±51.23 months for patients aged zero to five months, 108.15 ±69.12 months for six to 23 month old children, and 103.85 ±54.15 months for 24-72 month old children. There was no difference in follow-up for the three groups. The youngest group had the largest proportion of postop glaucoma (0.3) and highest average number of surgeries in the first postop year (1.7) whilst the older group had the smallest glaucoma proportion (0.14) and lowest number of surgeries (0.61); significant differences. There was no difference in pseudophakic refractive change per year across groups. A difference was found in rate of refractive growth across groups: zero to five months (-19.82 ±5.23), six to 23 months (-22.32 ±7.45) and 24-72 months (-9.64 ±11.95). The authors conclude that age at primary IOL implantation affects rate of refractive growth especially for children under the age of two. They recommend using age-adjusted assumptions when planning IOL surgery in young children.