Optometry Articles

What are progressive multifocal lenses?

Progressive multifocal lens is a kind of lens with different degrees of up and down, which is used to see far from the top and near from the bottom. The distance degree fixed above the lens to the near degree fixed below the lens does not change suddenly, but gradually transitions between the two through the gradual change of refractive power. Compared with ordinary lenses, it has many advantages. The lens looks like a single light lens, and the dividing line of degree change can not be seen. Not only the appearance is beautiful, but more importantly, it protects the age privacy of the wearer (for the wearer of Reading Glasses), and there is no need to worry about divulging the age secret due to wearing glasses.

Since the change of lens degree is gradual, there will be no image jump. Comfortable to wear and easy to adapt. So it's easy to accept. Because the degree is gradual, the substitution of regulation also increases gradually according to the shortening of visual proximity. There is no fluctuation of regulation, which is not easy to cause visual fatigue. Clear vision can be obtained at all distances in the visual range.

Such a pair of glasses can meet the use of far, near and middle distances at the same time. In particular, it has brought good news to teachers, doctors, musicians and computer operators, because these people not only need to see distant and near objects, but also can see intermediate objects such as blackboard, piano score and computer screen most of the time. This is impossible for any lens except progressive multifocal lens.

Who are progressive glasses suitable for?

Progressive multifocal lenses have no degree limit. They can be worn for myopia, presbyopia or moderate astigmatism, but not everyone can wear them. There are two types of asymptotic multifocal lenses on the market, one is hard and the other is soft. The main difference between the two designs lies in the length of the asymptotic corridor. The hard designed progressive film has a short progressive corridor (the degree from far to near is too fast), and the peripheral aberration is relatively small. In order to ensure the vision of each distance, less vertical dimensions are required. For example, the juvenile progressive film belongs to this design, but because its gradual channel is short, the gradual change process is too fast, and this design is difficult to adapt compared with the elderly; The gradient channel of the soft design progressive film is relatively long and the peripheral aberration is relatively large. However, due to its long gradient corridor, the gradient process is relatively gentle, which is easy for the wearer to adapt and suitable for the person with poor adaptability.

If a person can and is willing to accept new things and can understand and adapt to the temporary discomfort caused by progressive multifocal lens, we suggest that he can have one. If he has serious symptoms such as hypertension and vertigo, or has misunderstandings about progressive multifocal lens and is unwilling to adapt, he'd better not try. Because wearing progressive multifocal glasses for the first time may appear: slight dizziness, shaking when walking, exercise and be careful when going up stairs.

The space feeling changes, the distance judgment of the object and the depth feeling change. The first wearer should not drive immediately and do strenuous exercise. When looking close, you need to turn your eyes down, and your eyes feel slightly uncomfortable. Look at the object through the blurred vision area around the lens, and the object becomes blurred. Therefore, when the first wearer looks at things, he turns his head more and his eyes less. He tries to look at objects in the far use area, near use area and medium distance area.