They were approved for use in the U.S. within the last year. They are only approved for the treatment of small amounts of nearsightedness, up to about 3 diopters. The Lasik surgery, by contrast, can correct up to 14 diopters of nearsightedness. It is unclear at this time how successful these Inpacs will be. A lot of doctors are concerned about the possible long-term side effects of placing these plastic devices into the cornea.
Diopters are the units of measure for the strength or power of a lens.
Patients with severe nearsightedness would have 6 or more diopters. Numbing drops are then applied to numb the eye and a device known as a lid speculum is placed in the eye to keep the eye opened during the surgery. The patient is asked to look at a blinking target light during the surgery. The surgeon then places a device on the eye, which applies a strong suction force. This raises the pressure in the eye and the eye becomes very firm.