Compared with single vision glasses, bifocals are multi-focal glasses.
Compared with single vision glasses, bifocal glasses, trifocal glasses belong to multi-focus glasses, and the types of trifocal glasses are diverse. When choosing the optical properties of a trifocal lens, it can be thought that the lens is made up of three different lenses: the main lens, the distal optic regions, two appendages. One for the distance and one for the proximal area.
Sometimes they need to be adjusted by professionals.
Some connecting parts of glasses will be loose, but some people do not care about them and make casual changes. In reality, the change of the lens frame is very technical. The distance between the lens and the glasses will affect the effective strength of the lens, so the adjusted glasses need to be 12 to 14 mm away from the eye. The optical center of the lens should be aligned with the pupil position, and the nose pad, the temples should be consistent with the contact part of the bridge of the nose and the ear, without pressure and pain. Therefore, the lens frame must be adjusted by a professional optician. Especially some special lenses (progressive multi-focus glasses) need to be repaired regularly.
The Cons of Progressive Lenses
In this section, we will show you the cons of progressive lenses. There are some problems with progressive lenses especially when walking up and downstairs. Since the reading correction is at the bottom, the stairs may appear closer than they actually are. But this problem can disappear if you have adapted to them.
In addition, all measurements must be exact when creating a pair of progressive glasses. The optical center of the lenses must be placed exactly in front of your pupils in order to the lenses to work correctly.
Also, some people may find that it is difficult to adapt the progressive lenses, and it may take a few days to adapt them.
These are the progressive glasses’ pros and cons. If you want to a pair of progressive glasses, Koalaeye glasses are recommended. Koalaeye glasses are stylish and come at a cheap price. Besides progressive glasses, Koalaeye Optical also provides other eyeglasses, such as blue light block glasses, polarized glasses, sunglasses, and so on. So, if you need a pair of progressive glasses, try Koalaeye glasses.
Bifocal vs Varifocal Glasses: What Are Their Differences?
The above part has introduced some basic information about bifocal glasses and varifocal glasses. So, what are their differences?
- Bifocal glasses have two different prescriptions in one lens, while varifocal glasses have three different prescriptions in one lens.
- There is a distinct line between different prescriptions in bifocal glasses. Varifocal glasses allow getting through other prescriptions smoothly.
- Varifocals can give you a vision at any distance.
- Bifocal glasses are more cost-effective than varifocal glasses.
However, they also have some similarities. Both glasses can be used to correct presbyopia vision. So, when you choose glasses, you can decide to choose bifocal glasses or varifocal glasses based on your needs. If you want to get a pair of corrective glasses online, Koalaeye Optical is recommended. It is an online glasses store and provides all kinds of eyeglasses, sunglasses and frames. In addition, these glasses are stylish and come at a cheap price.
How To Choose Better Night Driving Glasses?
You should select light alloy material and polymer material with memory, collision resistance, and low friction coefficient characteristics. It can effectively prevent the damage to the eyes and face caused by the friction of the broken lens frame during use. Because of its specific molecular structure, the chemical resistance is good. In the high-temperature environment. it is not easy to deform and can withstand 350 degrees in a short time of high temperature, not easy to melt and combustion. The glasses made of this material are light and strong, and the ears will not be uncomfortable because of wearing the glasses for a long time.
Buy Prescription Glasses Online Step By Step
1. Before you can buy glasses online, you’ll need a current glasses prescription.
2. Select an online retailer, comparing online retailers like EyeBuyDirect and KOALAEYE until you find the best fit for your needs.
3. Shop for the perfect frames according to face shape, frame favorites, the budget, etc.
4. Once you’ve found your perfect frames, you’ll enter your eyeglasses prescription and pupillary distance to choose the lenses.
5. Read over the fine print on return/exchange policies and product warranties before you complete your order.
6. Having picked your perfect frames, entered your prescription information, added any lens coatings and upgrades, and checked your online retailer's warranty and return policy, it’s time to complete your order.
OSKIDE night driving glasses
With excellent night vision, this product can provide you with clear vision when driving at night, on cloudy or rainy days. In addition, it can protect you from the sun's harmful rays and bright headlights. Made of durable materials, they are flexible enough to withstand strenuous exercise and high-intensity outdoor activities. Equipped with polarizing lenses, they reduce glare and improve clarity when bright lights may be distracting, so they are perfect for sunny days or night driving. And it has UV 400 UV protection function. It protects your eyes from harmful ultraviolet and blue light.
