Ocular lens

Definition

The ocular lens, also known as the eyepiece, is the lens located at the top of a microscope through which a user looks to observe the magnified image. It typically provides additional magnification in combination with the objective lenses.

5 Must Know Facts For Your Next Test

1. The standard magnification of an ocular lens is usually 10x but can vary between 5x and 30x.
2. It works in conjunction with the objective lens to further magnify the specimen being observed.
3. The total magnification of a microscope is calculated by multiplying the magnification of the ocular lens by that of the objective lens.
4. Ocular lenses often contain measurement scales called reticles or graticules for estimating sizes of microscopic features.
5. High-quality ocular lenses are designed to minimize optical aberrations, such as chromatic and spherical aberrations.

Review Questions

• What is the typical range of magnifications provided by ocular lenses?
• How do you calculate the total magnification of an image viewed through a microscope?
• What feature might be included within an ocular lens to help measure microscopic features?

Related terms

Objective Lens:

The primary lenses on a microscope that provide most of the specimen's initial magnification.

Total Magnification: The combined magnifying power achieved by multiplying both ocular and objective lenses' magnifications.

Reticle (Graticule): A scale or grid incorporated into an ocular lens used for measuring dimensions within a microscopic field.