Color process of Contact lenses
Pigment printing process
It refers to the direct printing of pigments or patterns on the inside of the lens and then drying, which is the main production process of poor-quality chromatic contact lenses. Usually, small factories and small workshops use this method. The lens is being phased out because the pigment can easily seep out from the surface during wearing, causing discoloration and staining, and irritation to the eyes, which is a big risk.
Pigment build-in process
To be specific, the lens made by sandwich technology is a three-layer structure, the front and rear are colorless transparent layers, and the middle is a colored layer. After the processing of sandwich technology, the color layer is wrapped in the middle of the front and rear transparent layer, so that the pigment will not contact the eyes, which will not cause irritation and injury to the eyes. The downside of this process, however, is that the lenses are slightly thicker than normal contact lenses and are less oxygen-permeable, so they are not suitable for long-term wear.
The pressed film manufacturing process
This is a relatively new method of a similar sandwich process, and the color (pattern) is also made between the front and rear layers of the lens. But the color (pattern) is used to fill in the film process. During lens curing, the pigment seeps into the material instead of sticking to the surface. It feels as if the lens is covered in color within a single layer. This reduces the middle layer and makes the lens thinner, which naturally makes it more comfortable and permeable to oxygen.
Are children optometry matched with glasses the same as adults?
The optometry of children is one of the main works of optometry. Compared with adult optometry and glasses, children's optometry and glasses have both commonness and particularity. It is an area at the intersection of pediatric ophthalmology, pediatric optometry, and optometry. It requires the operator not only to have the knowledge of ophthalmology but to have the basis of children's ophthalmology and children's optometry. And they should be an optometry expert. Dealing with children's refractive problems is as much an art as a technique.
A round face fits on a square frame.
The human face of a round face is shorter. So they had better match the slender frames that take curves slightly to reconcile the whole feeling. Angular and square frames are helpful to modify facial lines (prominent longitudinal lines). This can promote strengths and avoid weaknesses so that your face appears contour.
The Disadvantages of Polycarbonate Lens
In this section, we will show you the disadvantages of polycarbonate glasses.
First, the polycarbonate lens is expensive than other regular lenses. It can cost up to double the price of regular eyeglasses.
Second, compared with high-index lenses, polycarbonate glasses have a lower abbe value, which is used to measure the dispersion of light for different eyeglasses lens materials. Polycarbonate lens rates lower mean they have the potential to cause slight chromatic aberrations in your peripheral vision.
Third, compared with Trivex lens, polycarbonate lens has bad durability since they are thinner and lighter.
About Polarized Sunglasses
Polarized sunglasses only absorb the reflected light of the object itself, presenting what is being seen, making the field of view clearer and thus reducing eye strain. In addition, the light through a bumpy road, water, and other places also can produce irregular diffuse light. The polarized lens can be this kind of optical filter, only absorbing the reflection of the object itself. Because of its high-efficiency filter layer, the UV blocking rate of the polarized sunglasses is 99%, which can effectively reduce UV damage to the eyes. And if you are driving, fishing, traveling, skiing, it is recommended to choose more powerful polarized sunglasses.
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.
Why were eyeglasses invented?
Glasses are commonly used for vision correction, such as reading glasses and myopia glasses, but they are sometimes used for cosmetic purposes if special lenses are not available. Safety glasses provide eye protection for a construction worker or laboratory technician against flying debris. They provide protection against visible and near-visible light or radiation. Sunglasses can improve vision in bright sunlight and can protect your eyes from excessive UV damage. Special glasses can be used to view specific visual information. Sometimes glasses are used purely for fashion or aesthetic purposes. Even eyeglasses used to correct vision come in different kinds of styles, with frames made of plastic, metal, wire, and other materials.
