Visual acuteness: The first step is to record visual acuity. Patients who require remedial lenses should wear them during trying. Visual acuity in each eye is tested as the opposite eye is covered.

The set of the microscope closest to the eye is the eyepiece or ocular based from Latin oculus, eye, as in oculist. The objective of a simple microscope magnifies the object and sends the enlarged image up the tube to where the ocular picks it up and magnifies it again. There are microscopes, and devices on more ordinary usages such as measuring the length of such an incredibly tiny cell as a bacterium.

It also allows you to perceive depth, because the two eyes see the specimen through separate lenses. The magnification of the dissecting microscope is not as great as the compound microscope. It does, however, enable the viewer to observe large specimens at a magnification up to 30X.