| Revision as of 00:12, 29 November 2002 editCamembert (talk | contribs)Extended confirmed users18,991 edits not all modern multi-focals have smooth transitions← Previous edit | Revision as of 00:16, 29 November 2002 edit undoMintguy (talk | contribs)11,899 edits nearsightedness is called short-sightedness in the UK, Australia and much of the English speaking world outside of the USNext edit → | ||
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| Spectacles fitted with ]es are a very common means of correcting ] problems such as ] (commonly called ''nearsightedness'' or ''short-sightedness''), and ] (commonly called ''farsightedness'' or ''long-sightedness''). Myopic people cannot focus at long distances; people with hyperopia cannot focus at close distances. ] is mismatched focussing horizontally and vertically. ] is limited flexibility in focussing. None of these conditions are diseases. | Spectacles fitted with ]es are a very common means of correcting ] problems such as ] (commonly called ''nearsightedness'' or ''short-sightedness''), and ] (commonly called ''farsightedness'' or ''long-sightedness''). Myopic people cannot focus at long distances; people with hyperopia cannot focus at close distances. ] is mismatched focussing horizontally and vertically. ] is limited flexibility in focussing. None of these conditions are diseases. | ||
| Glasses can be very simple. Magnifying lenses for reading that are used to treat mild |
Glasses can be very simple. Magnifying lenses for reading that are used to treat mild hyperopia and presbyopia that can be bought off the shelf, but most glasses are made to a particular prescription, based on degree of myopia or hyperopia combined with astigmatism. Lenses can be ground to specific eyes, but in most cases standard off-the-shelf prescriptions suffice, but require custom-fitting to particular frames. | ||
| As people age, their ability to focus is lessened and many come to need multiple-focus lenses, ] or even ] to cover all the situations in which they use their sight. | As people age, their ability to focus is lessened and many come to need multiple-focus lenses, ] or even ] to cover all the situations in which they use their sight. | ||
Revision as of 00:16, 29 November 2002
Spectacles (also called eyeglasses or glasses, slang cheaters) are lenses worn in a frame before the eyes. Modern spectacles are typically supported by pads on the bridge of the nose and by arms placed over the ears. Historical types of spectacles included the pince nez, monocle and lorgnette.
Spectacles were originally made from glass, but many are now made from plastic due to the danger of breakage and the greater weight of glass lenses. Glass lenses, on the other hand, are much less prone to scratching.
Spectacles fitted with corrective lenses are a very common means of correcting focus problems such as myopia (commonly called nearsightedness or short-sightedness), and hyperopia (commonly called farsightedness or long-sightedness). Myopic people cannot focus at long distances; people with hyperopia cannot focus at close distances. Astigmatism is mismatched focussing horizontally and vertically. Presbyopia is limited flexibility in focussing. None of these conditions are diseases.
Glasses can be very simple. Magnifying lenses for reading that are used to treat mild hyperopia and presbyopia that can be bought off the shelf, but most glasses are made to a particular prescription, based on degree of myopia or hyperopia combined with astigmatism. Lenses can be ground to specific eyes, but in most cases standard off-the-shelf prescriptions suffice, but require custom-fitting to particular frames.
As people age, their ability to focus is lessened and many come to need multiple-focus lenses, bifocal or even trifocal to cover all the situations in which they use their sight.
Traditional multifocal lenses have two or three distinct viewing areas, each requiring a conscious effort of refocusing. These were originally separate lenses, as invented by Benjamin Franklin, an early eyeglass-wearing celebrity.
Some modern multifocal lenses give a smooth transition between these lenses, unoticeable by most wearers. Other glasses wearers sometimes have lenses specifically intended for use with computer monitors at a fixed distance. On the other hand, many people simply have several pairs of glasses, one for each task or distance.
Glasses are often regarded as unattractive (see Dorothy Parker), and many people prefer to wear contact lenses for that reason. Contact lenses also provide much improved peripheral vision.
On the other hand, many people are attracted to people who wear glasses, and glasses are available in a very wide range of styles, materials, and even designer labels.
Spectacles can be a major part of personal expression, from the extravagance of Elton John and Dame Edna Everidge from Groucho Marx to John Denver all the way to the varied professional personas of eyeglass-wearing knowledge workers.
For some celebrities, glasses form part of the identity. Sen. Barry Goldwater continued to wear lensless horn-rimmed spectacles after being fitted with contact lenses because he was not recognizable without his trademark glasses.
In popular culture, spectacles were all the disguise Superman and Wonder Woman needed to hide in plain view as alter egos Clark Kent and Diana Prince.
Wearers of spectacles have also been stereotyped as intelligent or even geeks. This is because the first people to wear glasses were those who did a lot of reading in an era when most people were illiterate.
Other kinds of spectacles include tinted protective lenses, ranging from sunglasses, which protect the eye from glare and ultraviolet radiation, to specialized units that protect against extreme brightness and are used for welding and viewing eclipses.
Prescription sunglasses, which combine protection from bright light with vision correction, have become fairly common. Some glasses have photo-sensitive lenses that darken as the light grows brighter. They are sunglasses and indoor glasses in one.
Spectacles fitted with coloured or polarized lenses can be used to view three-dimensional images.
Old Saying
- The optimist looks at the world through rose-tinted spectacles.