Lenz

After you have added Lenz to Firefox, just visit any web page and click the Lenz button on your browser toolbar. Choose a lens shape and the lens will follow your mouse movements.

FAQ:

Q: Why does the Lenz add-on ask if it can "Access your data for all websites"? A: In order to make the lens effect, the add-on takes a screenshot of the current webpage and modifies the area the lens is over. Taking the screenshot triggers that warning from the Firefox system. I do not store or transmit any data at all from your web browser.

Q: How do I turn it off? A: To turn off the magnification effect, click the same icon that is currently active (either the hemisphere or the semicylinder).

Q: Why does the lens disappear when it goes over certain parts of the web page? A: Lenz cannot receive mouse movement notifications when the mouse is over an embedded "iframe" tag in the web page. These tags are sometimes used for advertisements or embedded videos. Since the lens would just seem to be stuck, I decided to just hide it until the mouse moves back to the main part of the page.

Q: What determines the location where the lens displays when its controls are being changed? A: It goes to the last place you clicked.