Intacs

Corneal ring implants (Intacs) are inserted into the third layer of the cornea.

After an incision is made and a tunnel created, two small plastic crescents are inserted in a rotational manner in between the stromal layers of the cornea.

A stitch is used to close the wound. Intacs can only correct mild amounts of nearsightedness (from -1.00 diopters to -3.00) and cannot correct astigmatism.

Though Intacs are removable (prescription returns to pre-operative status), it is not clear if other corrective procedures would be possible after Intacs. Intacs have a removal rate of 7% and have side effects such as glare, halos, blurry vision and problems with night vision in about 10% of patients.