The Oqual: a new device for measuring the optical quality of the anterior segment of the human eye.

An attachment to (Haag-Streit and Topcon) slit-lamps is described. This permits projection of a patterned target into the eye and the visual or photographic analysis of the details of the image reflected from the posterior surface of the crystalline lens. A numerical assessment can then be made of the optical quality of the crystalline lens as a whole, although scanning it is also possible. The attachment has also been used successfully for the objective assessment of the patient's post-operative visual acuity following kerato-refractive procedures.