Contact Lens Materials - Non-HEMA materials
The non-HEMA materials are hydrophilic soft lens material, which does not contain HEMA components. They are stronger and more oxygen permeable than most HEMA polymers.
The water content of regular hydrogel lenses varies from 30% to 58%. When oxygen passes through the hydrogel, it needs to be carried by water molecules in the material. Therefore, the higher the water content of the lens, the higher the oxygen permeability value. The softer the lens, the more comfortable it is to wear, which is conducive to the metabolism of the cornea. However, at the same time, the higher the water content of the lens, the faster the water evaporation, easy to dehydration, and easy to cause dry eyes. A lens with high water content has low material density, poor durability, and easy breakage, so they are suitable for making lenses that are frequently changed or discarded. On the contrary, the lens with low water content has good formability, easy operation, durability, and is not easy to dehydrate and cause dry eyes.
How To Choose Better Night Driving Glasses?
Choose and buy glasses to use a special night with anti - strong night driving lens. The demand is to block 80-90% of the strong lights and harmful lights, and at the same time to make the road more clearly. Choose glasses with thicker lenses, they are more durable and protect the eyes of drivers against irritation and accidental breakage. As common sunglasses and color-changing glasses are only suitable for daytime wear, wearing them at night will seriously affect the driver's vision.
Common light yellow night driving glasses can only block a small amount of light, and is not very suitable for night driving glasses standards. Therefore, in the choice of lenses of night driving glasses, we must do the selection and demonstration of the national authority of the formal institutions to test products, to achieve the desired effect in actual use. Don't buy products that are not up to standards from vendors. Such products not only do not block the lights but may affect the driver to see the road ahead, affecting the safety of the train operation.
What is a progressive lens?
Progressive multifocal lenses are lenses with different upper and lower powers for seeing far above and below for seeing near. The distance from the fixed far power above the lens to the near power fixed below the lens does not change suddenly, but a gradual transition between the two through the gradual change in refractive power. Compared with ordinary lenses, there are many advantages. The appearance of the lens is like a single vision lens, and the dividing line of the power change is not visible. Not only is the appearance beautiful, but more importantly, it protects the age privacy of the wearer, and there is no need to worry about revealing the age secret due to wearing glasses.
Since the change of the lens power is gradual, there will be no image jump. It is comfortable to wear and easy to adapt. So it is easy to be accepted. Because the degree is gradual, the replacement of the adjustment effect is gradually increased according to the shortening of the short distance. There is no adjustment fluctuation, and it is not easy to cause visual fatigue. Clear vision can be obtained at all distances in the visual range.
Such a pair of glasses meets the use of long-distance, near-use and various distances in the middle at the same time. It is especially good news for teachers, doctors, music workers, and computer operators, because these people not only need to see far and near objects clearly, but most of the time they also need to be able to see middle distance objects such as blackboards, piano scores, and computer screens. . This is not possible with any lens other than progressive lenses.
Recognize the identity
First of all, we should identify the logo of the pure titanium glasses frame. Usually, pure titanium glasses frame is on the supporting piece of the frame, and the inside of the temples is pure titanium.When online glasses need glasses retailers provide detailed pictures, to check if there is pure titanium.Usually, pure titanium frames are marked with 100% TITANIUM or PURE TITANIUM on the temples or lens.BetaTitanium stands are labeled BetaTitanium or β Titanium, which varies slightly from manufacturer to manufacturer.
Glasses are no longer ordinary daily necessities. A pair of glasses not only can assist eyesight, but also enhance or even change your temperament. In addition to the material, color, and shape, when choosing glasses, the most important thing is to match your face. Some frames are really good-looking, but they will be scary if they don’t match the shape of your face. Today we will talk about how to choose glasses according to your face shape.
If you need reading glasses when using a computer, you may want to choose a lower reading glasses power. This is because most people view their screen from a greater distance from their eyes than when they are reading a book or a magazine.
However, if you need reading glasses for looking at something very close or very small, you may need a pair of stronger power glasses.
In most cases, when two reading glasses’ powers seem equally suitable, choose the glasses with the lower power. Picking reading glasses that are too string typically will cause more discomfort problems than reading glasses that are a little too weak.
Where to Buy Anti-Glare Glasses?
From the above, you have learned some benefits of anti-reflective glasses. So, you may wonder where I can buy anti-glare glasses. So, to buy the anti-reflective glasses, Koalaeye Optical may be a good choice. Koalaeye Optical is an online optical store, providing all kinds of eyeglasses, sunglasses, and frames. You can choose the best suitable glasses for yourself. Besides, Koalaeye Optical offers a free shipping service so that you can get the glasses at home with great convenience.
