Key Stage 3
Meaning
A lens is a shaped piece of glass, or other transparent material, that can be used to focus an image of an object.
About Lenses
- A lens can be convex or concave.
- There is a lens in the eye that is used to focus an image onto the retina.
- Glass lenses can be moved relative to a screen until an image is focused but the lens in the eye can change shape to focus light.
Key Stage 4
Meaning
A lens is a shaped piece of glass, or other transparent material, that can be used to focus an image of an object.
About Lenses
- A lens can be convex, also called a converging lens or concave, also called a diverging lens.
- Lenses can be used to create a real image by focussing light onto a screen, or they can create a virtual image by looking through the lens.
- The shape of the lens determines its focal length. For a convex lens (converging lens) the focal length can be found by focussing the image of a "distant object" onto a screen. The distance between the screen and lens is the focal length.
- There is a lens in the eye that is used to focus an image onto the retina.
- Glass lenses can be moved relative to a screen until an image is focused but the lens in the eye can change shape to focus light.