Employing modern microsurgical techniques and a specially designed tensiometer, four separate 4-mm corneal incisions, each with a different suture material, were incorporated into a single rabbit’s cornea and at varying intervals of survival, the breaking strain and histological reactions of each incision were analysed. Unsutured incisions, reaching only 3.4% of total intact corneal strength by the 6th, 8.8% by the 12th, and 34.9% by the 56th post-operative day, emphasised the need for sutures in corneal and cataract surgery. The strength of healing sutured wounds occurred in two separate phases. In the first 6 days, where suture reaction was minimal, wound strength was dependent on the presence of a suture, being directly related to basic suture strength. In this phase, 8–0 black twisted silk was superior to all four sutures tested. In the second phase between 10 and 56 days, with the development of suture reactions, there appeared to be little difference in the strengths of wounds sutured with different materials.