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A pair of dental loupes featuring in-lens magnification. There is a loupe light mounted on the bridge of the loupes and side shields (not shown) on the temples to protect a dentist's eyes from splatter. Dentists, hygienists, and dental therapists typically use binocular loupe glasses since they need both hands free when performing dental ...
Hand-held binoculars range from small 3 × 10 Galilean opera glasses, used in theaters, to glasses with 7 to 12 times magnification and 30 to 50 mm diameter objectives for typical outdoor use. Compact or pocket binoculars are small light binoculars suitable for daytime use.
It has been proposed that glass eye covers in hieroglyphs from the Old Kingdom of Egypt (c. 2686–2181 BCE) were functional simple glass meniscus lenses. The so-called Nimrud lens, a rock crystal artifact dated to the 7th century BCE, might have been used as a magnifying glass, although it could have simply been a decoration.
An optical prism is a transparent optical element with flat, polished surfaces that are designed to refract light. At least one surface must be angled — elements with two parallel surfaces are not prisms. The most familiar type of optical prism is the triangular prism, which has a triangular base and rectangular sides.
1 – Objective lens 2 – Schmidt-Pechan prism 3 – Eyepiece. A monocular is a compact refracting telescope used to magnify images of distant objects, typically using an optical prism to ensure an erect image, instead of using relay lenses like most telescopic sights.
Design features of an operating microscope are: magnification typically in the range from 4x-40x, components that are easy to sterilize or disinfect in order to ensure cross-infection control. There is often a prism that allows splitting of the light beam in order that assistants may also visualize the procedure or to allow photography or video ...
Adjustable focus eyeglasses are eyeglasses with an adjustable focal length. They compensate for refractive errors (such as presbyopia) by providing variable focusing, allowing users to adjust them for desired distance or prescription, or both.
Spectacles (glasses) to correct refractive errors of the eye; not invasive. Contact lenses. to correct refractive errors of the eye; a little invasive. Phoropter. used in refraction testing. Tonometers. used to determine the intraoccular pressure (IOP) - useful in glaucoma; video link for various types of tonometers.
There are three primary types of optical telescope: Refracting telescopes, which use lenses and less commonly also prisms ( dioptrics) Reflecting telescopes, which use mirrors ( catoptrics) Catadioptric telescopes, which combine lenses and mirrors.
The dispersion of light by glass prisms is used to construct spectrometers and spectroradiometers. However, in lenses, dispersion causes chromatic aberration, an undesired effect that may degrade images in microscopes, telescopes, and photographic objectives.