The disadvantages of progressive lenses
- The field of view in the near and middle distances is relatively narrow.
- The adaptation time is longer and patients with greater astigmatism are not suitable for wearing.
- The peripheral aberration is large, and there will be large astigmatism in the periphery.
Can the TR90 frame be changed?
TR90 material was originally made in Italy. It is difficult to color the frame, and usually, the color is painted on the outside. It can float in saltwater. It is suggested that the lens should be a water first to prevent overheating of the lens. Then, at the end of the nose, hinge, or the temple, carefully fold it in until it is comfortable to wear. You can use a household hair dryer to blow heat first, which can play the role of softening. Note that the hairdryer should be moved when heating, and do not aim at only one place. TR-90 is the most popular ultra-light material in the world at present.
Why do glasses with the same prescription feel different?
The clarity of the lens changes. In addition to the case of the frame, the lens will be yellow or slightly scratched during use due to long-term absorption of ultraviolet rays, oily contact, dry rubbing by the user, etc., and the clarity of the lens will be affected. However, the clarity of newly equipped glasses tends to be higher, and the comparison between the two will cause discomfort. It is recommended that the new glasses can be used early the next morning. After a night's rest, the eyes will be easier to adapt to the new glasses. Under normal circumstances, new glasses generally require an adaptation period of about a week. After a few days of continuous wearing, the uncomfortable symptoms will disappear.
Choose clear glasses with the right materials for kids.
A critical point for children to choose frames is to think about the weight, to avoid wearing for a long time, or they will be uncomfortable, unstable, easy to slip. It is recommended to choose an ultra-light plate or TR90 lens frame, which has good chemical properties, good thermal stability, with no deformation, good recovery, and no side effects, lightweight, and convenient material.
How Do Bifocal Glasses Work?
After learning some basic information about bifocal lenses, you should know how the bifocal glasses work.
With a pair of bifocal glasses, it would be convenient since they combine all your vision needs into a pair of glasses and you do not need to switch two pairs of glasses frequently. Bifocal glasses are usually designed to for those people who are over the age of 40-45 that need additional help with their near vision due to the effects of presbyopia where the crystalline lens inside the eye naturally begins to lose its ability to focus on near objects.
If you work in the office, you may need a pair of bifocal glasses. The top distance vision in the top of the lens can be used for meetings or presentations and the near vision in the bottom of the lens can be used to look at the computer screen or at documents.
How do bifocal reading glasses work?
Bifocal reading glasses have two different lenses on the same lens. The top of the lens is your normal distance prescription, while the bottom is for close-up viewings, like reading. The two lenses allow you to alternate between them by moving your eyes up and down as needed. A bifocal lens is a type of lens that has two different areas of vision: one for close range and one for long-range. Typically, the upper section covers remote vision and the lower section covers reading. With a traditional bifocal lens, you can see the difference between the two lenses because the lower curve is a little different.
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.