The evolution history of glasses (2/2)
Meanwhile, August Muller, a German medical student, was experimentation with his lenses. In his 1889 paper, he described that although he can make the size of the lens conform to the proportion of his eyes, he had severe pain in his eyes after embedding for half an hour, but his myopia had been improved after subsequent correction.
As we all know, oxygen in the body is transmitted through blood red blood cells, but 80% of the oxygen required by the cornea comes from the air and 15% from the limbal vascular network. This trait makes eye contact lenses, early models have been faced with two major problems: one problem is almost entirely cover glass lens material white, small and light hard to find; it also brought another serious problem, is not conveying oxygen through the glass lens, and the eye once the lack of oxygen, corneal edema will gradually lead to decreased vision, it is not acceptable.
In addition, the early invisible scleral lenses need to expand the shape of the eyeballs of the patients to make models, and then make glasses based on the mold. The extension process is quite uncomfortable, and the lens is often skidded and slippery, easy to fall out of the eye, or difficult to take out. Therefore, the contact lenses invented at this time can not be put into promotion, when only less than 500 people in the world wore the glass contact lenses.
By 1937, transparent plastic materials were replaced by glass materials. Scientists Theodore Ernst Obrig and Ernst Muller made the world's first plastic hard contact lens with this material. The biggest feature of the lens is that it is lighter and easier to wear than glass, and the effect of corrected vision is good and the life is longer. Later, this hard contact lens material has been improved and has been used to today.
The earliest glass stealth lenses, because of poor air permeability, hardness and other disadvantages, wear the longest time can only endure 4 hours. Until 1948, the United States optometrists Kevin Tuohy occasionally found in the lens didn't have to cover the whites of the eyes, so the lens wearing time extended hours. Subsequently, Tuohe pioneered a small lens called Microlens. This kind of lens is a transparent plastic. It polishes the edges of lenses. It only covers the cornea, and even smaller than the cornea. The thickness is thin, and it can be comfortably worn for a whole day. To his surprise, this modified plastic lens can be kept in its original position even after blinking. Since then, a contact lens that can be popularized in clinical practice and as a correction of ametropia of the patient's eyes is really born. Kevin Tuohy's invention completely changed the history of contact lenses. However, there are still some shortcomings in this kind of lens. First, the lenses are hard, which may cause wear to the cornea. Two, the edges of new lenses are somewhat warped, which means that lenses may fall off any time. Until the invisible soft mirrors came out, these problems were solved.
In 1952, a material specialist in a university in Prague discovered a new material compatible with living tissue, but they didn't intend to make contact lenses. In 1954, the Czech scientists group invented a kind of hydrophilic resin material that will soften and fit into the eyes after absorbing water. Scientists immediately recognized the potential of this material to produce corrected vision lenses, and began experimenting on animals.
Compared with the ordinary hard, this material is soft, comfortable, moisten is good, have certain permeability. At the time, these discoveries were ridiculed by colleagues in other optical research fields, but a scientist named Otto Wichterle ignored the ridicule and began to study in his own kitchen. In 1961, Weitele and his wife made 5500 pair of contact lenses at home, their success eventually gained widespread concern in the field of science. Wichterle is thus called the "father of invisible soft mirror".
The United States registered Bausch & Lomb this technology patent, and in 1971 the development of its series of soft contact lens. The company sold 100 thousand stealth mirrors in the first year. Since then, the invisible soft lens with its comfortable, easy to adapt to the characteristics of the immediately replaced the hard lens, the lenses have undergone historic renewal.
In 1974, a breathable hard mirror material (silicone acrylate) was born to improve the oxygen permeability and the lens can be worn safely for the night. Due to the involvement of silicon components, the oxygen permeability of the lenses is further improved. On the basis of which, various porous rigid mirror materials, such as fluorosilicone acrylates and fluoromers, are derived.
In 1981, CIBA Vision made the first soft astigmatism contact lenses, and produced the first pair of beauty contact lenses and the first pair of double contact lenses in second years. In 1983, CIBA Vision company pioneered dioxygen contact lens care system, improve the quality of disinfection of lens. In 1986, Johnson was the first to throw out contact lenses. In 1987, the company pioneered the use of contact lenses Bausch & Lomb full of contact lens care solution, advocate comprehensive care.
In 1998, CIBA Vision has developed a breathable soft lens material, and bring the oxygen permeable principle is completely different, the inventor of the world's highest oxygen permeability contact lenses are worn for 30 days to meet the people's desire to improve the hard lens discomfort, wear comfortable and clear, become so far the ideal contact lenses.
In twenty-first Century, the development of contact lenses was made again