Iris-fixated intraocular lens Iris-fixated intraocular lens Iris-fixated phakic intraocular lens is an intraocular lens that is implanted surgically into the eye and fixated to the iris to correct myopia (nearsightedness). Early models were sutured to the iris with a stitch; the claw fixation method made iris stitching unnecessary. The iris-claw lens is fixated to the anterior iris surface by enclavation of a fold of iris tissue into the two diametrically opposed claws of the lens. The fixation sites are located in the midperiphery of the iris, which is immobile during pupillary movement. This lens was modified into a convex-concave design and manufactured as
Telecentric lens Telecentric lens A telecentric lens is a compound lens that has its entrance or exit pupil at infinity; in the prior case, this produces an orthographic view of the subject. This means that the chief rays (oblique rays that pass through the center of the aperture stop) are parallel to the optical axis in front of or behind the system, respectively. The simplest way to make a lens telecentric is to put the aperture stop at one of the lens's focal points. An entrance pupil at infinity makes the lens object-space telecentric. Such lenses are used in machine vision systems