Basic principles of progressive lenses
The surface of the progressive slice is divided into five regions. There are far, middle, and near optical areas. They are respectively corresponding to see distant objects, middle distance objects in the near distance objects. One pair of glasses is multi-purpose. In appearance, it is not very different from regular lenses. There is no clear dividing line. Distal use area: The area above the progressive slice is the distal use area, which is used to correct the distal refractive error. Proximity area: from the matching lens cross down, the refractive power of the lens continuously increases the positive degree, which is used to see close objects. Gradient area: The channel connecting the far and near areas. It is an area of regular change from top to bottom, used for transitioning and seeing objects at intermediate distances. The length of the gradient is very important for the wearer's adaptation. The rate at which the degree of gradient changes is called gradient. The gradient can be uniform or variable. Peripheral area: Changes in the surface curvature of the lens will lead to aberrations in the peripheral areas on both sides of the lens, mainly astigmatism and prism effect, which will interfere with a vision to a certain extent, resulting in blurred vision or distortion. And it will affect the wearer's adaptation to the progressive lens.
The lens material
Lens material affects the effect of protecting our eyes, so we should choose the kind of driving glasses made of polarized lens, which can effectively reduce the dazzling lights, and can filter out the redundant lights. When used at night, the powerful light is softened and the vision is clearer, thus ensuring the safety of drivers and relieving eye fatigue. If you can, let the seller dim the light when you buy, feel the softness and clarity of the light after wearing the product.
How to handle rusty spectacle frame?
Skin allergies are after the rust of the spectacle frame, so we have to solve the problem of rust of the spectacle frame by physical isolation. Apply a layer of transparent nail polish on the metal surface, or add an anti-allergic sleeve on the temple of the eyeglasses so as to separate the skin from the metal by resin. Both of these methods isolate the skin from the spectacle frame, effectively preventing corrosion of the spectacle frame caused by sweat and grease.
Colored Clear sunglasses
The glasses style is distinctive, with an exaggerated outer edge and blue clear design. They show youth breath. The small eyebrow on the glasses side that shows faintly lets the whole look more stereoscopic. Relative to other colorless clear sunglasses, color clear glasses convey a strong youth breath. It is all color design that greatly enriched the color part of the overall image.
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.
Consider the elements of frame comfort.
What we need to know is that the frame exists first as a positioning device for the lens, and secondly as a beauty. The pupil is consistent with the optical center of the lens, so it should not be too high or too low. The horizontal direction is not skewed, and there is no one high and one low phenomenon. Bilateral symmetry is a standard for manufacturing enterprises. Non-mechanical symmetry is for the wearer. The frame should be adjusted according to the size of the wearer's face. The frame is not easy to slide down, and frequent slide is prone to the phenomenon that the pupil is too high and low to match the face.
Silhouette Rimless Glasses
They provide a range of options for rimless, full-frame, and half-frame styles. Their optics lab allows personal prescription lenses to be mounted on any frame and sunglasses. Here, fashion and function come together in an ultra-light titanium eyewear frame, using exclusive hingeless polycarbonate lenses. Minimal weight, hingeless construction, and form combine timeless framing styles with different kinds of lens shapes and breakthrough technologies.
