The purpose of the study was to observe the changes in histological thickness of retina in developing human fetuses. The total thickness of human fetal retina from 13 to 40 weeks of gestational ages was measured on 56 eyeballs of 28 fetuses. Thickness of retina was measured on both side of optic nerve on nasal and temporal side under light microscope by ocular micrometer in micron meter. The total thickness of retina increases as gestational age increases also the retinal layers develops at different gestational ages.