What Do Trifocal Lenses Do?
Trifocal glasses can provide correction for some eye conditions including presbyopia and cataracts. Presbyopia often occurs in people who are between the age of 40 and 60. People’s eyesight starts to deteriorate and they are unable to focus at near. Wearing trifocal glasses can help correct blurred vision, eye strain, and headaches. The trifocal intraocular lens placed during cataract surgery can also resolve cataracts.
From above, you have learned some information about trifocal lenses. But what are the pros and cons of trifocal lenses? So, in the following section, we will focus on the advantages and disadvantages of trifocal glasses.
What Are Transition Lenses?
Transition lenses, also called photochromic glasses are eyeglasses lenses that change their colors with light. The transition lenses darken in the sunlight and lighten in the softer light or the dark. These transition lenses provide the convenience of sunglasses without having to wear them over your prescription glasses and having to constantly switch between the two.
But there are some common transition lenses problems. So, we will list some of them. Are transition lenses worth it? After reading this post, you will find them.
Disadvantages of pure titanium frames
The material is soft, the glasses can not be made more delicate, only the lines are thicker, in order to ensure stability and strength.Usually, when you are not wearing a pure titanium glasses frame, it is better to put them in the case of glasses, to avoid pressure deformation.
What's wrong with your not clear phone's screen, low brightness, or even black screen when wearing polarized sunglasses?
There is a polarizing plate in the display structure of the mobile phones, which comes from the photoelectric modulation effect of the display screen. There is a polarized light absorption axis in the polarizing plate, which is consistent with the polarized light absorption principle of the polarized sunglasses. If the polarization absorption axes of the two are parallel, the screen can be seen. When they are perpendicular to each other, the light emitted by the screen will be absorbed by the sunglasses, and the light cannot reach the eyes, leading to the phenomenon of the black screen or low brightness. There may be differences in the direction of the absorption axis of the polarizer. So after wearing the polarized lenses, when you see low brightness or black screen, there are two different situations: landscape screen and portrait screen.
Clean Glasses Properly
If the glasses are dirty, don't just wipe them with other cloth. If you use some hard cloth to wipe, it is easy to cause scratches in the lens. Generally speaking, the following cleaning methods are all feasible.
1. Use neutral or alkaline cleaning agent. Remember, toothpaste cannot be used as a substitute for the cleaning agent for spectacle lenses. General optical shops also sell lens cleaners in small bottles, which are easy to carry.
2. Go to the optical shop for professional ultrasonic cleaning. General optical shops provide free cleaning services. The ultrasonic cleaning machine can fully clean every gap and groove of the glasses.
3. Rinse the lens with tap water. Hold the frame in one hand and the cleaner in the other hand. Rub it slowly against the lens, and then rinse it off with clean water. Then wipe it with a glasses cloth or let it dry naturally.
In addition to the glasses cannot be cleaned with alcohol, you should also pay attention to their placement for daily maintenance. Try to avoid putting it under high temperature, and avoid oily, smoke, etc. If you don't use them, put them in the glasses case.
Progressive lenses and single vision lenses
Single vision lenses are the most commonly used prescription lenses. This lens type has a single field of view or a prescription ability of the entire lens and can be used to correct myopia (nearsightedness) or hyperopia (supervision).
Progressive multifocal lenses are lenses with different upper and lower powers for the upper part to see far, and the lower part to see near. The distance from the fixed power above the lens to the fixed power below the lens does not change suddenly, but there is a gradual transition between the two through the gradual change in refractive power.
Acquisition of optometric degrees when buying glasses online
The degrees are mainly got from three places: physical store paid optometry data, hospital optometry data, previous degree (remember or retest). If you are in the hospital for optometry, it should be noted that there must be test glasses to try on, if there are no test glasses to try on, the data is not accurate.
