Goldmann three-mirror lens

• ·         Goldmann three-mirror lens

consists of four parts; the central lens and three mirrors set at different angles. Because the curvature of the contact surface of the lens is steeper than that of the cornea, a viscous coupling substance with the same refractive index as the cornea is required to bridge the gap between the cornea and the goniolens. It is important to be familiar with each part of the lens as follows: C-PEG

1. 1.       The central part provides a 30° upright view of the posterior pole.
2. 2.       The equatorial mirror (largest and oblong-shaped) enables visualization from 30° to the equator.
3. 3.       The peripheral mirror (intermediate in size and square-shaped) enables visualization between the equator and the ora serrata.
4. 4.       The gonioscopy mirror (smallest and dome-shaped) may be used for visualizing the extreme retinal periphery and pars plana.

It is therefore apparent that the smaller the mirror, the more peripheral the view obtained.