How to buy prescription glasses online
Consumers should choose different styles of frames according to their age and professional characteristics. Because everyone has different face shapes, different interpupillary distances, and different diopters, the size of the frames should vary from person to person.
Lenses are divided into glass lens, resin lens, and PC lens, and you can choose according to your preferences. The glass lens has a stable refractive index, good abrasion resistance, and stable optical performance, but it is relatively heavy and easy to break. Resin lens with high light transmittance is light, safe, and not easy to break, but the surface is easy to wear. PC lens has a high refractive index, but the surface is easy to wear.
Advantages of aspheric lenses
In reality, aspheric lenses were originally born to improve the marginalized optical properties of spherical lenses. The aspheric lens with special coating treatment has perfect visual performance, with a clearer, more comfortable visual effect. You can hardly feel the presence of aspheric lenses when you put them on. So you can enjoy the ease brought by aspheric lenses. They are more natural and more realistic, having less visual distortion. The aspheric lens can be designed with a flatter base arc, which not only makes the appearance beautiful but reduces the peripheral magnification so that when others look at the eyes of the people who wear glasses, the size will not change much.
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 Test Blue Light Glasses (Amber and Red Lenses)
This section will show you how to test blue light glasses with amber or red lenses.
1. The Black and Blue Squares Test
1. Prepare black and blue paper.
2. Wear your blue light glasses after sunset and check whether both paper appear black.
3. If they do not appear black, your blue light glasses can’t block all blue light.
2. RGB Color Chart Test
1. Prepare an RGB color chart as follows.
2. Wear your blue light block glasses and look at the chart.
3. After wearing blue light blocking glasses, if the B section becomes black and the G section becomes darken, it shows that your blue light glasses block blue light and some filter some green light.
4. The less bright the green circle with your blue light glasses, the better they are.
Besides the above ways, you can ask the professional optician to perform a professional blue light glasses test, which would be more reliable. After that, you can know whether your glasses work effectively to block blue light.
What’s more, if you want to purchase a pair of effective blue light blocking glasses, you can try Koalaeye Optical. It is cheap and provides free shipping services.
The lenses of prescription glasses
Common materials for lenses include glass, resin, and PC. The glass is fragile and heavy, and few people wear it anymore. PC film is tough and not fragile, but it is not resistant to high temperature and the surface is easily scratched. The most common type of lens on the market today is the resin lens, which is light in weight, hard to break, and reasonable in price. At present, it is generally recommended that you choose resin sheets, and it is recommended that people with ultra-high myopia choose glass sheets.
Generally, lenses can be divided into spherical and aspherical surfaces according to different curvature designs. When choosing, refer to the degree of the eye. For people with lower degrees, There are fewer differences between the two shapes. For people with moderate to high myopia, aspherical lenses will have better imaging effects and clearer vision.
When choosing a lens, a parameter that is often mentioned is the refractive index. Common refractive indexes are 1.56, 1.60, 1.67, and 1.74. With the same degree, the higher the refractive index, the thinner the lens.
Geometric Cat-Eye glasses
Geometric cat-eye glasses are a big trend this year. They accentuate the personality and the shape of your face. If you have a square face, a geometric cat-eye frame will add some angle to your face, which can be very flattering. Cat-eye frames are both sexy and serious, drawing the image of a determined woman who knows what she wants. Choose the modern contours of Treble. Retro cat-eye black frames are a great option for women working in a business setting, as they give you a smart and mysterious look that is sure to emphasize your professionalism.
It is more reasonable to use a visor
According to experts, if using the sun visor above the seat can solve the problem of dazzling sunlight, it is generally not recommended to use sunglasses. Although high-quality sunglasses can effectively reduce the impact of light on human eyes, they will more or less affect vision. Driving as a high-risk behavior, misjudgment of the environment can easily lead to accidents. If you really want to use sunglasses while driving, it is recommended that you develop a habit of wearing sunglasses to walk or work during your daily. Also, you can choose dedicated driving sunglasses. What needs to be reminded is that if your sunglasses are not usually worn, don't use them alone in the car.