Irides of rabbit, cat, monkey, and human eyes were exposed to ruby laser coagulation in an attempt to produce iridotomies. One monkey iris was exposed to the argon laser. The ability to produce an iridotomy was directly related to the degree of iris pigmentation. There was no observed damage to the corneas, lenses, or retinas of animals exposed. A method for producing iridotomy in the tan-brown iris by ruby photocoagulation had a high success rate.