Standard and modified occupational multifocal lenses
Most people with presbyopia can get satisfying vision correction from conventional bifocal or trifocal lenses. But for those spending all day long in a job or hobby that requires only near vision or distance vision, special occupational bifocals or trifocals are needed. These special occupational multifocal lenses have unusual placement of near, intermediate and far vision zones of the lens, meeting different and specific needs.
Occupational lenses with double near zones
In most cases, near vision zone is placed at the bottom of a multifocal lens. But some professionals such as auto mechanics, librarians and mail clerks require both overhead near vision and downward near vision. Double-D lenses are the perfect choice for this kind of tasks. A double-D lens has a D-shaped bifocal segment at the bottom and another upside-down D-segment at the top. Double-round lenses are similar to double-D ones.
Occupational lenses with a wider intermediate zone
While double-D lenses favor near zones, another type of occupational lenses named E-D lenses emphasize on intermediate zones. An E-D trifocal lens has a top half part for distance vision and a bottom half part for intermediate vision. The near vision segment only occupies a small D-shape area of the bottom part. With a wide area of intermediate zone, this type of trifocal lenses is suitable for television production workers.
Occupational lenses through unusual placement
Occupational multifocal lenses can be achieved by simply positioning common multifocal lenses in unusual ways. Ordinary trifocal lenses are properly fitted by placing the top line to be just below the pupil. By placing trifocal lenses higher, the wearer is needless to look down or tilt back the head to get near vision. This type of occupational lenses fits a pharmacists but is not suitable for drivers.
A golf-specific occupational lens can be achieved by placing a round-top bifocal lens low and in the outside corner of one lens only. In this way, the near vision zone is put aside but it is still enough for the golfer to read a scoreboard. What’s beneficial, distance vision can be significantly expanded, which is helpful for shot-making and lining up a putt.
The extra benefits
Compared with regular multifocal eyeglasses, occupational glasses in different forms allow related wearers to see with improved flexibility. Some jobs really require unusual viewing ways, which can not be achieved through standard reading glasses, bifocals and trifocals. Each of the above occupational lenses is designed for a specific group of people exclusively. To some extent, they are called task-specific glasses. With the help from occupational glasses, people who get benefits can further improve occupational productivity. In detail, wearing occupational glasses that offer dedicated vision aid is a good way to maximize productivity on the job.
Taking computer users as an example, occupational glasses with a wider intermediate zone will offer extra help. These people can get more visual flexibility if they spend many hours per day on a computer. The rate of developing symptoms of Computer Vision Syndrome can be minimized. In addition, being free from eye fatigue, stress and even headache will certainly improve computer reading efficiency and thus enhance productivity.