The aim of the study was the presentation of changes in thickness of each layer of a developing cornea, that came into being under an influence of caffeine which was administered to chicken embryos. Research materials were 26 chicken embryos from breeding eggs that had been incubated. Breeding eggs were divided into two groups: control (n=30) in which Ringer liquid was given, and experimental (n=30) in which teratogenic dose of caffeine was administrated - 3.5 mg/egg. In 36th hour of incubation solutions were given with cannula through a hole in an egg shell directly onto amniotic membrane. After closing the hole with paraffin, eggs were put back into incubator. On 10th and 19th day of incubation corneas were taken for morphometric and morphological analysis. In experimental groups reduction of corneal thickness, thickening of corneal epithelium and corneal endothelium as well as Bowman's and Descemet's membranes, decrease of thickness of corneal stroma in comparison with the control group have been observed. Caffeine causes thickness changes of all layers and decreases the total thickness of a developing cornea.