What instrument is used to view the retina?

The instrument used to view the retina is the ophthalmoscope. This device is specifically designed to illuminate and magnify the interior of the eye, allowing healthcare professionals to examine the retina, optic disc, and blood vessels. By providing a clear view of these structures, the ophthalmoscope helps in diagnosing various eye conditions and diseases, such as retinal detachments, diabetic retinopathy, and glaucoma, which can significantly affect vision if left untreated.

In contrast, other instruments such as a retinoscope are used primarily to determine refractive errors in the eye rather than visualize the retina directly. An endoscope is intended for viewing internal structures of other body cavities and is not used in eye examinations. An optometer, while related to measuring refractive error, does not serve the purpose of observing the retina. Thus, the ophthalmoscope stands out as the correct choice for directly assessing the retinal health of the eye.