There have been mainly three types of multifocal eyeglasses, bifocals, trifocals and progressive ones. Some people may say that bifocal safety glasses also fall into this group. It is undeniable that the first pair of eyeglasses was created for visual correction. Even if there are numerous styles of spectacles that have been developed in order to meet people’s demand for fashionable look in the eyes, eyewear products for visual aids are still the majority in the market. Another testimony to this claim is that near all types of eyeglasses have been named according to their functionalities. For instance, regular prescription eyeglasses are so named because of their prescription power. Sunglasses won the name due to the function of blocking sunlight. There are many other similar examples or testimonies. Bifocal eyeglasses, trifocal eyeglasses and progressive readers have nearly the same principle of naming.
According to the above discussion, curious individuals may want to know exactly those functional differences between one type and another. A bifocal lens and a trifocal one do have dramatic difference or differences. This is the main task of this writing. From a superficial perspective, bifocals and trifocals differ in the number of focal points in a single lens. What is a focal point? In brief, a focal point is a type of lens power. A bifocal lens has two different focal points and a trifocal one has three. In addition, a focal point is able to provide one kind of visual aid. For instance,bifocal eyeglass can deal with two different eye problems at the same time. And trifocal lenses are capable of offering vision correction in three visual zones.
What is the detailed functional difference between bifocal eyeglasses and trifocal glasses? Presbyopic patients who use bifocal reading glasses a lot may have experienced discomfort or even headache after spending long hours on computer work. This problem can be removed by the use of trifocal eyeglasses, which provide visual help during intermediate visual tasks including computer work.
C: Bifocal eyeglass differs from trifocal eyeglasses in the number of focal points in a single lens. Trifocals can deal with materials within the intermediate visual zone, which is beyond bifocal glasses.
Firmoo.comis the fastest growing online community selling affordable yet high quality prescription eyeglasses, prescription sunglasses and other eyewear. Firmoo’s return and refund policy makes your purchase with Firmoo risk-free. Firmoo offers wide selection of prescription sunglasses frames and lenses (tinted and photochromic).