Also called “RK,” this is an older refractive surgery style in which a diamond knife is used to make radial cuts in the cornea. These incisions change the shape of the cornea and can correct nearsightedness. This technique was invented by a Russian ophthalmologist in the ’70s and was very popular in the ’80s and early ’90s. While effective, some people with RK continue to have corneal shape fluctuations decades later and go on to become farsighted. While a successful procedure, this technique has since been supplanted by more predictable laser procedures like LASIK and PRK.