Observable area from a plane mirror. You can modify the size and position of the man and also drag the mirror vertically.

How rays enter  the eye after reflection from a plane mirror. This animation  illustrates idea  like:  image point/object point, left/right, and geometric construction process. Click and drag the ball of wool to raise it up vertically.

By changing its curvature, the eye’s lens causes  light rays to converge so that they focus on the retina – a process known as accommodation.  You can observe this by dragging the miniature Eiffel Tower in the animation. This focusing is only possible beyond a limit called the "punctum proximum" or "near point". Otherwise, the image is  formed behind the retina and so is blurred.
The diagram is not drawn to scale !

Any illuminated object reflects part of the light shining on it but only the polished surface of a mirror can render a perfect reflection. The light rays from an actual object bounce off the mirror to give a virtual image. With a flat mirror, the real object and the virtual object are symmetric and appear to be at the same distance on either side of the plane of the mirror.

Symmetry rules at work in the reflection process explain how an image is formed by a plane mirror.

Object A (a teapot) can be moved around, illustrating the symmetry rules at work in the reflection of light rays.

Reflection of light from a plane mirror. Click and drag the mirror around the screen. Rotate it by clicking an dragging the red “handle”.

In its simplest form, a magnifying glass is a single convex lens which causes the light from the object being observed to refract and converge on the eye. The enlarged image provided is sharp at the focal point of the lens where all the light rays converge. Microscope and telescope eyepieces are complex magnifying devices using several lenses.

The magnification ilustrated is 2X.

Ray diagram using the secondary focal points.

The “handle” on the black ray allows you to change the angle of incidence. Click three times on “play” to activate each of the three steps in the construction.