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.
Production technology of progressive lenses
In addition to the evolution in design, the production technology of progressive lenses is also constantly improving: the most representative one is the free-form technology. The emergence of free-form surface technology makes the production more flexible and rapid and can realize a more personalized design. For now, progressive lens design is done on the inside surface of the lens by a computer-controlled lathe, as if a master engraver could carve a piece of stone into a work of art.
Is it safe to buy contact lenses online?
Today's optometry is not a simple measurement of your degree. Through some professional instruments, they check the health of your eyes to see the health of your eyes. Is it appropriate to wear contact lenses at present? If there is inflammation in the eyes, it is forbidden to wear contact lenses, and if you wear them, it will cause harm to the eyes. If you buy online, you can't enjoy professional eye examination, try on, test, and other professional inspection and matching services that you can enjoy in professional stores, nor can you enjoy professional wearing and nursing guidance from professional staff. People often overlook eye problems that may result from the wrong choice of contact lenses, which are often overlooked by consumers.
Pure Titanium Glasses Frame Brand - Seiko
Seiko glasses, I believe, everyone has heard of this brand because Seiko glasses in the glasses industry are still relatively famous.Seiko is founded in 1881. It is one of the top ten pure titanium eyeglass brands in the world and enjoys a high reputation.So far, brand products have been involved in watches, optics, and other fields, and have done very wonderfully in different fields.Compared with similar products, its pure titanium spectacle frame is not only better than quality, but more in detail. Seiko's frame is divided into two categories: men and women.
There are business and professional styles.The two categories are divided into the full-frame and half-frame glasses frame. It can be seen that, in the style, Seiko glasses have a more clear, very specific positioning.For the common white-collar or company executives, the Seiko glasses frame is the most popular.
Use your two hands to wear and take off the glasses.
When you pick and wear glasses, you need to grab the temples with both hands and take them off. When you pick and wear glasses with one hand, it is easy to cause deformation and loosening of the glasses. According to the convention of international glasses design and manufacture, you should fold the left temple first. When placing glasses, keep the convex side of the lens up to avoid scratches on the lenses.
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.
How do drivers wear glasses or sunglasses better?
We should pay attention to the dim light at night on the impact of vision, At night, for the people who wear glasses, it is best not to drive, but to prevent fatigued driving. If you need to drive, you must choose clear and appropriate optical glasses. When the light is strong in the field, it is advocated to wear light-colored sunglasses with appropriate degrees to ensure driving safety. When wearing glasses to drive, for the observation of road conditions, we should focus on the use of the head movement. Do not use eyes to move, to prevent the effect of the prism, especially the patient with high myopia should pay special attention. Shaded sunglasses, coated with reflective material, block out light from above and increase horizontal and lower light, which makes it easier to see the platform. Clip-on sunglasses are suitable for people who wear glasses themselves. You can go straight with a pair of myopic sunglasses for a higher price.