Abstract.Background:  Central corneal thickness is significantly greater in full‐term infants than in adults. Very little is known about corneal thickness in premature infants. Methods:  Measurements of central corneal thickness and horizontal corneal diameter were carried out in 35 premature babies (70 eyes) undergoing screening for retinopathy of prematurity. Initial measurements were taken at ∼ 31 weeks gestational age and at intervals until term was reached. Results:  Babies born at ∼ 31 weeks have very thick corneas which show a progressive and statistically significant decrease to term. Conversely, horizontal corneal diameter shows a progressive significant increase to term. A very strong inverse correlation was found between these two parameters. Conclusion:  We demonstrate that premature infants have thick corneas and small corneal diameters. Central corneal thickness decreases dramatically from ∼ 31 weeks to term and is mirrored by a significant increase in corneal diameter.