Microscopes have been in use in various forms for more than 3,000 years. The first types were extremely simple magnifiers made of globes of water-filled glass or chips of transparent crystal. Ancient Romans were known to use solid, bead-like glass magnifiers; Emperor Nero ( a.d. 37-68) often used a bit of cut emerald to augment his poor vision.

The first lenses, which were used in primitive eyeglasses, were manufactured in Europe and China in the late thirteenth century. By this time, lenscrafters realized that most clear glass or crystal could be ground into a certain shape (generally with the edges thinner than the center) to produce a magnifying effect. All of these single-lens magnifiers are called simple microscopes.

Until the turn of the seventeenth century, most simple microscopes could provide a magnification of 10 power (magnifying a specimen to ten times its diameter). About this time, the Dutch...