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Eyeglasses: Lens Material And Design Types
Protective Coating For Your Eyeglasses
Protective coatings for lenses are another option. Anti-reflective coatings reduce unwanted reflections and help to alleviate glare or eyestrain, especially during night driving. Another type of coating helps to portect the eyes from ultraviolet light (UV). With the exception of polycarbonate lenses, most lenses are not inherently UV protective. This extra coating emliminates UV light, protecting the eyes from harmful radiation.
Prescription Sunglasses
One simple option for lenses that correct vision while protecting the eyes from sunlight is prescription sunglasses. For patients who would rather wear only one set of eyeglasses indoors and out, photochromatic lenses are a good option. Photochromatic lenses change tint according to the amount of light they receive, darkening in the sunlight and lightening indoors.
Protective coatings for lenses are another option. Anti-reflective coatings reduce unwanted reflections and help to alleviate glare or eyestrain, especially during night driving. Another type of coating helps to portect the eyes from ultraviolet light (UV). With the exception of polycarbonate lenses, most lenses are not inherently UV protective. This extra coating emliminates UV light, protecting the eyes from harmful radiation.
Prescription Sunglasses
One simple option for lenses that correct vision while protecting the eyes from sunlight is prescription sunglasses. For patients who would rather wear only one set of eyeglasses indoors and out, photochromatic lenses are a good option. Photochromatic lenses change tint according to the amount of light they receive, darkening in the sunlight and lightening indoors.
Many are surprised when they learn how many options they have when it comes to eyeglasses. Among these options for eyeglasses are the various lens designs. The basic eyeglass design is single vision, and all-purpose lens designed to correct distance vision. There are multifocal eyeglass lenses that
are designed to correct both distance vision and near vision (the upper
portion is focused for distance vision, while the bottom portion is
used for up close activities such as reading). Multifocal lenses can be bifocals, trifocals, or progressive lenses. Bifocals have one line separating the top part of the lens, for distance, from the bottom portion, for close viewing. Trifocal lenses focus light in three areas-distance vision, intermediate vision, and near vision. One disadvantage of bifocal and trifocal eyeglasses is the abrupt dividing line between each area of the lense. Progressive lenses
alleviate this problem by replacing these sharp divisions with a smooth
transition between distance and near vision. By eliminating the
lines between the focal areas, progressive eyeglasses also tend
to "look" better, but each focal area is relatively small because more
space on the lens is used for the transitional areas.
Choose The Right Lens Material For Your Eyeglasses
Lens material is another option for eyeglasses. Traditionally eyeglass lenses were made of glass. Today however, most lenses are plastic. Plastic eyeglasses are lighter, more flexible, and less likely to shatter. One type of plastic lens is a "high index" lens, which is very thin and light. High index lenses are most often recommended when the need for visual correction is high, to reduce the "coke bottle" appearance of thick glasses. Eye care professionals recommend another option, polycarbonate lenses, for patients who wear glasses for sports or other potentially hazardous activities. Polycarbonate is a safety lens material that is highly impact resistant.
Lens material is another option for eyeglasses. Traditionally eyeglass lenses were made of glass. Today however, most lenses are plastic. Plastic eyeglasses are lighter, more flexible, and less likely to shatter. One type of plastic lens is a "high index" lens, which is very thin and light. High index lenses are most often recommended when the need for visual correction is high, to reduce the "coke bottle" appearance of thick glasses. Eye care professionals recommend another option, polycarbonate lenses, for patients who wear glasses for sports or other potentially hazardous activities. Polycarbonate is a safety lens material that is highly impact resistant.
Above: Bifocal, Trifocal And Progressive Lens Types.
