Ocular Lens

∞ generated and posted on 2016.01.14 ∞

Eyepiece of a compound microscope.

The eyepiece is the second lens in a compound microscope in terms of the direction of movement of light. The first lens that light passes through post the specimen instead is known as the objective lens. The pathway of light is:

light sourcecondenseriris diaphragmstage → object/specimen → objective lensocular lens → eye or camera.

Ocular Lens

Figure legend: The ocular lens is the eyepiece and thus are found at the very top of the microscope. As this is a binocular microscope, there are two ocular lenses versus just one for a monocular microscope. Typically an ocular lens will provide 10× magnification, though note that even with two ocular lenses the resulting magnification is still just 10×.

A typical ocular lens will increase magnification by 10×. To determine the total magnification, you multiply the magnification by the ocular lens by that of the objective lens, e.g., a typical high and dry objective (40×) will yield a total magnification of 400×.