Role of positioning holes in intraocular lens glare.
We performed laboratory studies to determine the role of positioning holes in posterior chamber intraocular lens glare. Several areas of the lens optic were illuminated independently, and the scattering light off the lens was photographed. A conventional lathe-cut lens with four positioning holes on the optic produced the most intense light scattering. Scattering off nonilluminated areas was apparent, and it was suggested that the presence of positioning holes on the optic might contribute to the scattering. Optically complex areas including a hole, optic edge, a loop insertion, and optic-haptic junction produced the scattering in all lenses of various designs. An internal reflex inside the optic may occur, and complex or irregular structures in the optic may be a source of light scattering and some intraocular lens glare.