Advertisement Upgrade to remove ads

Victoria

Focal point

The point at which at which light rays passing through a lens come together

Concave lens

A lens that is thicker at the edges than it is in the middle

Retina

The light sensitive area at the back of the eye

Convex lens

A mirror that curves out ward

Reflecting telescope

An instrument for viewing distant objects that used a curved mirror at the of it's tube to gather light

Simple microscope

A microscope that uses a signal lens to magnify objects

Electron microscope

A viewing instrument that magnifies objects thousands of times by using a beam of electrons

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set