Eyeglasses have gone a long way since the first invention in the 13th century, and they are capable of solving lots of people’s eye problems life myopia or presbyopia. Eyeglasses can be considered as one of the greatest invention in human history assisting people to enhance the vision in one aspect. While the traditional eyeglasses take little effect when applied on the people with two or more eye problems, like the myopia and presbyopia simultaneously.
In the early 1784, a greatest American scientist with the name of Benjamin Franklin, who is also bothered by the nearsighted and presbyopic problems, happened to see much clearer both far and near at the same time when two kinds of lenses were overlapped in front of him. He then decided to put the two lenses in one frame, the upper part for the far view and the lower part for the nearer viewer. In this way, he did not have to switching the different glasses frequently, and this is deemed to be the first bifocal eyeglasses. As the times goes by, the sunglasses come into being to prevent eyes from sunlight hurting. So when the bifocal eyeglasses are tinted with colors, they are made into the bifocal sunglasses, which provide with both the bi-vision correction and the eye safety ensuring.
The earliest and the most traditional bifocal sunglasses are not designed friendly. The two lenses are roughly combined together, so they have distinct lines between the two lenses, and they are quite fragile, also it takes some time to adapt well when making some vision changing from the far to near or near to far. As the people who wear bifocal sunglasses are usually over the age of 40, the bifocal sunglasses with distinct lines can easily let out your secret – your age. So another type of bifocal sunglasses is designed to better satisfy more people’s demands. The lenses for presbyopia correction are molded into the lenses for nearsightedness correction in a variety of shapes and styles. The embedded part is relatively small as the vision area is not large for reading, while the other lens is bigger for wide viewing.
Besides, sunglasses are used as the decorations in daily life, more fashion elements are assimilated into the frames designs. The result is there are so many kinds of frames that you must get your favorite one pair.
Except for the development of the frame shapes of the bifocal sunglasses, the lenses also make great progresses too. The trifocal sunglasses are additionally to assist the intermediate view, thus make the view at any distance clearer. The progressive sunglasses are better when compared with the bifocal and trifocal sunglasses, as the transition between different areas are gradual, inducing no dizziness and headache.
However, bifocal sunglasses are still occupied large market share because of its reasonable price and powerful function. So if you suffer from the presbyopic eye problem as well as the myopia, hyperopia or astigmatism, join us to enjoy the reading in the beach when wearing the bifocal sunglasses.