Check the diopter of the eye, choose well-intended frames, many people will have questions: so many brands, types, functional lenses, which is suitable for me? Is it “I do my own thing” , “follow my heart” , or “Google Search” ?
A brand of Lens, different film, refractive index, different functions, different optical effects and other factors, there will be dozens or even hundreds of lens types, people hesitate.
Now, let’s talk briefly about the most widely used optical lenses. From the application point of view, there are single-light lenses and functional lenses.
Single Lens: Single Lens means there is only one optical center on the Lens, the optical center is made to correspond to the region of your pupil (that’s why the pupil distance is measured) .
single-light lenses are roughly divided into spherical, aspherical, biaspherical and free-form Lenses, free-form surfaces are currently the best in terms of reducing aberrations and distortion, but they are also slightly more expensive than other lenses. When you choose, you should according to the light of the eye and the degree of astigmatism to choose.
The Single Lens is the most basic and simple choice for those who have enough adjustment power, that is, those who do not have Presbyopia. But for people who are beginning to develop PRESBYOPIA, the monocular lenses can only be used at a fixed distance, or at a distance (for driving) , or at a distance (for desktop computers) , or at a close distance (for reading) , not both. So what do we do now? One Solution: a pair of glasses at a distance, and the other: progressive multifocal glasses.
Functional Lenses: including anti-fatigue Lenses, bifocal lenses, progressive multifocal lenses, children’s lenses to slow the development of Myopia (peripheral defocus lenses, bifocal + prism lenses) and so on.
Functional lenses have a lot, how to choose, one is to see our demand for glasses, two is the purpose of glasses. Take progressive multifocal lenses, which are functional glasses designed to meet the needs of farsighted and nearsighted people. For example, a teacher may need to look at the blackboard while communicating with the students in class (looking at the distance) and at the lesson plan (looking at the close use) . Or a department meeting may need to look at the slides and at the computer, also need to pay attention to the expressions of the participants, progressive multi-focus glasses on the big role.
It can be said that a pair of progressive glasses can solve the problem of being able to see clearly at different distances, and is no different from a single-light Lens in appearance, keeping our eyes “frozen” , but optometry and matching lenses are not as simple as a single lens.
1. Accurately measure the remote luminosity.
2, according to the age, the habit of close working distance, eye position, adjustment reaction, positive and negative relative adjustment, etc. . And choose the appropriate Channel (that is, the length of the transition zone between the far and near light zones on the Lens) in order to meet the needs of daily work.
3. Personalized frame adjustment. According to the height of each person’s nose bridge, the height of the ears and so on on the frame of the school, so that glasses wear comfortable.
4. Measurement of pupillary distance. The distance between the Near and far eyes, the height of the pupil in the Vertical Direction of the frame, and the mark on the selected frame are to be measured. In order to get more visual effect and reduce the interference of Aberration area to vision when wearing progressive lenses, the far and near light areas are in the corresponding area of pupil.
5. More measurements are required to design more comfortable progressive lenses: Eye Distance (the distance from the top of the cornea to the Lens) , the curvature of the frame, the tilt angle of the frame, the shape and size of the frame, etc..According to the proportion of head movement and eye movement, we choose the suitable type, which can reduce the influence of the aberration area on both sides of the Lens, shorten the adaptation period, and make the wearing more comfortable.
Therefore, the choice of Lens should not only focus on the brand or price, not the more expensive lens the better, blindly choose not to. Optometrists recommend that you choose lenses based on their own circumstances, eye needs and optometrists advice to choose the right lens for their own.
Post time: Jul-28-2021