Attempts were made (1) to develop an appropriate method for producing standardizable and reproducible experimental opacities of the cornea of rats and (2) to study quantitatively the course and intensity of the healing process of these corneal wounds. The right cornea of rats was cauterized by drops of 1.5 N HC1 over 30 s; the left one served as a control. The spontaneous course of wound healing, as well as the possible effect on this process of spray treatment with iodine brine or, for comparative purposes, with isotonic NaCl, was studied for 10 consecutive days by measuring the 24-h incorporation of 14C-labelled proline as a measure of de novo collagen synthesis. Spray treatment (1) abolishes the transient inhibition of proline incorporation observed in the unsprayed cornea on the first day after injury and (2) significantly advances the maximum collagen synthesis rate from day 3-4 to day 2 after the wound occurred. The position and magnitude of the 14C-proline incorporation peak are considered to be useful parameters for estimating corneal wound healing activity and its alteration by various agents. However, in this experimental design, it could not be proved that iodine has a specific effect.