Ophthalmologic collagen coverings derived from animal eyes and a process preparing such coverings comprising treatment of a fibrous tunic of an animal eye with an alkali metal hydroxide in a saturated solution of a salt of an alkali metal, followed by neutralization, dissolution in an aqueous solution of an organic acid, purification of the resulting solution of collagen by dialysis against a buffer solution while bringing the solution of collagen to a pH of 4.5 to 7.5 and drying the thus-obtained solution of collagen simultaneously with shaping spherical coverings therefrom.