What is the name of the instrument used to examine the eye?

The instrument used to examine the eye is called an ophthalmoscope. This device allows healthcare professionals to inspect the interior structures of the eye, including the retina, optic disc, and blood vessels. By using an ophthalmoscope, examiners can detect a variety of conditions affecting the eye, such as diabetic retinopathy, glaucoma, and other abnormalities.

An ophthalmoscope typically has a light source and a series of lenses that help in magnifying the view of the eye's interior. It is a vital tool for optometrists and ophthalmologists during eye examinations, making it essential for diagnosis and monitoring of ocular health.

Other instruments listed, such as the ophthalmometer, are used for different specific measurements (like the curvature of the cornea), while the optometer is used to measure refractive errors, and the optomechanism might refer to a mechanical aspect of optical devices but is not a commonly recognized eye examination tool. Each of these instruments serves unique purposes in eye care but does not fulfill the role of examining the eye in the comprehensive manner that an ophthalmoscope does.