Lenses

Definition

Lenses are optical devices that refract light to magnify or focus images, making them essential for viewing microscopic organisms. They are commonly used in microscopes to observe details not visible to the naked eye.

5 Must Know Facts For Your Next Test

1. Convex lenses converge light rays and are typically used in microscopes for magnification.
2. The objective lens is the primary lens responsible for initial magnification of specimens.
3. The eyepiece lens further magnifies the image produced by the objective lens.
4. Lens quality, such as numerical aperture and resolving power, directly affects image clarity and resolution.
5. Immersion oil can be used with high-power lenses to reduce refraction and increase resolution.

Review Questions

• What type of lens is primarily used in microscopes to magnify specimens?
• How does immersion oil enhance the performance of high-power lenses?
• Explain the roles of both the objective and eyepiece lenses in a microscope.

Related terms

Numerical Aperture: A measure of a lens's ability to gather light and resolve fine specimen detail at a fixed object distance.

Resolving Power: The ability of a microscope or telescope to distinguish two close together images as separate.

Refractive Index: A measure of how much light bends when it enters a material from another medium.