Here is a ray diagram showing how a convex lens produces an INVERTED IMAGE. The lens and cornea of your eye works in just the same way. The image on your retina (the back of the eye) is upside down, but your brain sorts this out.

In this diagram the magnification is times 2. The image is twice as large as the object.

Follow the 14 diagrams below to draw your own ray diagram for a convex lens. Make sure that you use a sharp HB pencil and a 30cms ruler. It is best to do the drawing on squared paper so that you get the optic axis at right angles to the lens and the parallel rays of light parallel.

You can change the values for the image height and distance and for the focal length, but some values will give you a smaller image than the object and some values will not give an image at all. I hope that you can read my handwriting.

When you look at something like another person, the image on your retina is smaller than the object, so the magnification is LESS than one.

            Last updated: 10 November 2006