A theoretical model for the eye of new-born infants.

A Gullstrand model for the eye of new-born infants is proposed, based on intra-ocular distances obtained by ultrasonography and lens radii measured on sections of deep-frozen preparations (v. Pflugk, 1909). Refractive indices of the media are assumed to be equal or nearly so to those of the adult eye, since no experimental data are available. The focal length of the model is 15.74 mm, the power 84.8 dptr, that of the lens alone 43.4 dptr, and the refractive error +2.8 dptr. A simplified model where the inner surface of the cornea is omitted, has a focal length of 15.63 mm, a power of 85.3 dptr and a refractive error of +2.4 dptr. When the data of v. Pflugk are analyzed statistically it is found that the spread of the lens power is considerably smaller than that which would be expected from the spread of the radii.