What is the primary purpose of a goniolens in ophthalmology?

A goniolens is a type of contact lens specifically designed for examining the anterior chamber angle of the eye, which is critical for diagnosing and managing various conditions related to glaucoma and other angle-closure problems. The anterior chamber angle is the area where the cornea and the iris meet, and it is not visible using standard observation techniques or equipment without proper instrumentation. By utilizing a goniolens, an ophthalmologist can achieve a wide view of this area, allowing for a detailed assessment of the structures involved and any potential abnormalities.

Other options pertain to different aspects of ophthalmic examination but do not apply to the primary purpose of a goniolens. Focusing light on the retina is related to the use of other optical devices and not specific to the functionalities of a goniolens. Measuring corneal curvature involves instruments like keratometers or topographers, which assess the shape of the cornea but do not involve viewing the anterior chamber angle. Visualizing the optic nerve is achieved through methods like fundus photography or optical coherence tomography, which focus on the back of the eye rather than the anterior chamber structures. Thus, the main utility of the goniolens lies in its ability to provide a clear view of the anterior chamber