Text seen through a<unk>  Jim Hutton as detective Ellery Queen, posing with a<unk>  A<unk>  is a convex lens that is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle. A<unk>  can be used to focus light, such as to concentrate the sun's radiation to create a hot spot at the focus for fire starting. A plastic Fresnel lens sold as a TV-screen magnifier A sheet magnifier consists of many very narrow concentric ring-shaped lenses, such that the combination acts as a single lens but is much thinner. This arrangement is known as a Fresnel lens. The<unk>  is an icon of detective fiction, particularly that of Sherlock Holmes.
Magnifying glass
Microscopy
Neurophotonics
X-ray vision
Laser microtome
Hounsfield scale
Gigli saw
Biopsy