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

The instrument used to examine the interior of the eye is the ophthalmoscope. This tool is specifically designed to enable a detailed examination of the retina, optic disc, and other structures located at the back of the eye. By shining a light into the eye and magnifying the image, the ophthalmologist or veterinary professional can identify various conditions such as retinal detachment, glaucoma, or cataracts.

In contrast, a neurometer is used to measure nerve conduction and assess nerve function, which is unrelated to eye examinations. A stethoscope is utilized to listen to sounds within the body, focusing primarily on the heart and lungs. An endoscope, while used to visualize the interior of hollow organs like the gastrointestinal tract, is not appropriate for eye examination. Thus, the ophthalmoscope is the correct and specialized tool for examining the eye's interior.