About GlassesUSA
GlassesUSA is an online prescription eyewear retailer. They have a wide selection of glasses and some contact lenses on their website.The GlassesUSA shopping experience is about convenience, removing the middleman, and reducing costs. You can use GlassesUSA.com from start to end of your shopping, without even leaving your home. GlassesUSA has a very wide selection of frames to choose from, no matter what your gender and age. They have been improving the way consumers buy glasses and adopting new technologies to improve the shopping experience. Each pair of glasses has a different style to suit different face shapes.
Is blue light blocking worth it?
There are two main problems with anti-blue glasses currently on the market. One is that the place to be prevented is not preventable, and the other is that people have color casts due to wrong protection and aggravate visual fatigue. Studies have shown that our eyes are the most intolerant of blue light in the 400-440 nanometer band. Therefore, current manufacturers mainly block blue light in this band when producing anti-blue glasses. However, the blue waveband of electronic products is between 450 nanometers and 490 nanometers, so most anti-blue glasses have little protection in this waveband. In addition, the blocking rate of anti-blue glasses is 20%~30% to achieve a good anti-blue light effect, but now the blocking rate of anti-blue glasses on the market has basically reached 80%~90%. All in all, these blocking blue light glasses cannot prevent the blue light in the 450-490 nanometer band, and their high blocking rate will also cause a color shift, which makes people more likely to have eye fatigue and headache.
In daily life, the intensity of blue light is low, not enough to cause damage to the fundus, so ordinary people do not need to wear anti-blue glasses unless they are working in extremely strong light conditions or working in special environments. To protect the eyes, it is more important for people to develop good eye habits. For example, wear a pair of suitable glasses and read insufficient light and at an appropriate distance. Avoid using electronic products for a long time. Take a break for 20 to 30 seconds every 20 to 30 minutes, and look at the distance regularly. If you have dry eyes while reading the electronic screen, remember to blink to 12 times per minute. It is best to wear sunglasses when outdoors.
Why do you need night-driving glasses?
Aging causes our pupils to become progressively smaller, so they don't dilate as quickly. A smaller pupil means less light reaches your retina, which makes it harder to see at night. The weak artificial light, and the fact that we can't see beyond these sources in the dark, exacerbate the dangers of night driving. For people wearing prescription glasses, the risk of driving at night is much greater. Driving can be stressful, especially if you have poor eyesight. This is especially true at night. If you have poor vision and drive at night, you're vulnerable to a number of potential hazards, and we're talking about prescription glasses for night driving. These glasses can play a big role in making you safer and more comfortable. They can even save your life. This is especially important as night vision decreases with age. When you drive at night, choosing the best prescription glasses for night driving can make your life easier.
How to Tighten Glasses by Yourself
After your glasses being used for a while, they will become loosen. In this situation, you may want to ask for a professional optical person to adjust or tighten it. It would be a way but with some inconvenience. So, you can also choose to tighten glasses by yourself.
Why the glasses will become loose? It can be caused by various reasons. Most people wear and remove their glasses several times every day. The back and forth movements of the glasses’ arms will increase the possibility that they will become loose.
If the glasses become loose, you can choose to tighten them by adjusting the temple arms. Most eyeglasses have a screw located at the temple hinge on both sides. To tighten glasses by yourself, you can choose to tighten this screw to make your glasses more comfortable or prevent them from slipping down your nose again. You had better check these screws periodically so you can tighten them before they fall out.
Types of aspheric lenses
There are two types of aspheric lenses: single aspheric surface (single aspheric surface for short, different from the outer aspheric surface and inner aspheric surface) and double aspheric surface (double aspheric surface for short). For the outer aspheric surface, convex is an aspheric surface and concave is a spherical surface. For the inner aspheric surface, a convex surface is a sphere, and a concave surface is an aspheric surface. In addition to correcting aberrations, the double aspheric lens also improves the effective field of vision compared to the single aspheric surface. When people's eyes look through the edge of the lens to see things, like driving when looking at the reflective mirror, it often affects vision because of the large aberration at the edge of the lens. Previous designs of aspheric plates have analyzed a single ray of light passing through the center of the pupil. Wavefront technology controls the entire beam of light passing through the pupil, eliminating high-order aberrations.
Features of TR90 Frame
It has the characteristics of wonderful toughness, crash resistance, wear resistance, and low friction coefficient, which can effectively prevent damage to the eyes and face caused by the fracture and friction of the frame during the movement. Because of its specific molecular structure, and chemical resistance, it is not easy to deform in a high-temperature environment. It's very elastic, and it doesn't deform. The use of thermoplastic materials in these frames provides pretty strength due to their flexible characteristics.
What to consider when buying eyeglasses?
The size of the frame should match the pupil distance so that the edge thickness of the lens is thinner and more comfortable to wear. The size should be proportional to the size of the face. The upper edge should not be higher than the eyebrow and the eyebrow should not be visible in the lenses. The shape of the frame should match the shape of the face and skin tone to meet aesthetic requirements. The rectangular face should choose a circular arc or arc transition frame. An inverted triangle face shape should choose one with a lower wide edge.
