Healing of surgical wounds, especially those of cataract and retinal detachment operations, is an important current topic in ophthalmology. Since collagen formation is a vital phase of wound healing, recent data indicating that carrageenin is a powerful stimulus to production of collagen makes it of interest to study the effect of this compound on ocular tissues. Carrageenin is a refined water-soluble hydrocolloid extracted from a seaplant, Irish moss (Chondrus crispus). It is a negatively charged polymer composed of two major fractions, of approximately equal proportions, lambda carrageenin (Fig. 1) and kappa carrageenin (Fig. 2). Both components are polydisperse, are composed of sulfatedd-galactose units and have molecular weights in the range of 100,000 to 500,000. Lambda carrageenin is composed almost entirely of these units linked through the 1-3 positions and kappa carrageenin contains one unit of anhydro-d-galactose for approximately every 1.2 units ofd-galactose. They form a highly viscous solution