Which Glasses for Computer Are the Best?
There is no such a thing that one type of computer glasses can fit all or is the best for everybody. When selecting glasses for screen protection, the visual ability, personal preferences, the type of work, the distance between the computer user’s eye and the monitor, and other factors should also be considered.
Bertoni polarized glasses
Bertoni polarized night vision driving glasses are made of strong, flexible, durable, and ultralight polycarbonate. Yellow polarization increases contrast, improves visual acuity, and filters out blue light. They are great for drivers, cyclists, and winter sports enthusiasts. The driving glasses with polarized yellow lenses block glare from headlights, reduce night driving glare, improve night vision, and improve color clarity and visual clarity. They are ideal for driving in low-light conditions. Most sports sunglasses glasses frames and goggles are made of polycarbonate because of their strong, thermoplastic, lightweight, and impact resistance features.
The design evolution of progressive lenses
Spherical and aspheric designs
The design of the front surface of the far-use area of the early progressive lens is similar to that of the ordinary spherical single vision lenses, so it is called a spherical progressive lens. Since 1974, the front surface of the far-use region of the lens is designed to be aspheric by designers, which not only reduces the peripheral aberration but makes the lens thinner, lighter, and less powerful.
Hard and soft design
For hard design, the channel is short, and the gradient is large. The near-use area position is high. The effective visual area of remote and near-use areas was larger. Peripheral astigmatism is relatively concentrated. Because surrounding astigmatism increases rapidly and the distribution is dense, the curve effect is more obvious. The gradient area is narrow. It is more difficult and takes longer for wearers to adapt.
Lenses with soft designs have slower gradients, longer gradients, and wider gradients. The angle of rotation of the eye from the far area to the near area is greater. It's easier to get used to. Compared with the hard design, the effective visual area of the far and near use areas is smaller, and the location of the near use area is lower.
Single, diverse, and individualized design
Initially, the progressive lenses used a single design, in which each basic curve was scaled equally and a luminosity combination was added within the range of its semi-finished lens blanks. The steepest base curve uses the same lens design as the flattest base curve. Lenses designers quickly realized that the overall performance of the lens could be improved by microcustomizing the lens design, leading to progressive lenses with multiple designs. This kind of design is called diverse design. By the mid-1990s, there was the emergence of individualized lens designs. In addition to using different gradients, these first individualized lens designs used steeper baseline curves with a slightly larger approach area to compensate for increased magnification and reduced field of view.
Symmetrical and asymmetric design
There is no difference between the left and right eyes in the symmetrical design of progressive lenses. As the eyes turn inward when they see near objects, the gradual gradient area gradually tilts to the nasal side from top to bottom, so the left/right progressive lenses should be rotated clockwise/counterclockwise respectively during processing. An asymptotic lens with left and right eye divisions is called an asymmetric design. The gradient is gradually and moderately inclined to the nasal side from top to bottom. The refractive force, astigmatism, and vertical prism of the two sides of the left and right gradient of the asymmetric design lenses are basically similar. At the same time, considering the characteristics of eye movement parameters in binocular vision, the peripheral aberrations of the corresponding positions of the left and right lenses were appropriately balanced to improve the visual effect of the wearer.
Points To Note When Choosing Frames
Choose a frame with lightweight, good elasticity, and stable structure. The lens frame with poor quality tends to deform in use, which affects the optical properties of the glasses. Pay attention to whether the two sides of the frame are symmetrical and whether it is fixed and safe enough. Pay attention to whether there are scratches on the surface of the frame. Just put on the glasses to feel if it is very tight or very loose, and they must be tight to reach the saturation condition. Pay attention to distinguish the advantages and disadvantages of the coating. The better coating frame has a uniform color, smooth surface, and clear identification. After using the frame with poor coating quality, the frame will soon rust and fall off, affecting the life of the frame, and even causing skin discomfort or allergy.
What Is Bifocal Lens?
Changes in vision seem to be related to age. Presbyopia, a common eye condition that occurs in middle age, causes changes in your eye’s ability to focus. But this condition can be corrected by wearing bifocal glasses.
Bifocal lenses are divided into two parts to accommodate two different prescriptions in one lens. One area of the lens will have one prescription (usually distance) and a segment in the lower half will have the other (usually near vision).
The bifocal glasses were invented by Benjamin Franklin, who solved his own vision problem by taking the lens from his reading glasses and distance glasses and cutting them in half. Then remade the cut lenses into a single pair of bifocals and put the distance lens on top and the reading lens on the bottom.
Can I order progressive glasses online?
Glasses belong to the half medical and half business industry, in addition to the price of glasses, frame style, lens quality, there is more need in professional glasses services. The quality will be very different. The refractive index, film layer, light transmittance, and anti-oil resistance of the lenses almost invisible to the naked eye will be very different, so the prices of different brands of glasses are not comparable. There are many considerations when buying progressive glasses online. If the lens is too far away from the eye, people with myopia may not be able to see clearly, and people with hyperopia may have too much diopter. If the distance is too close, the opposite is true. In addition to the accuracy of optometric data, we need to pay attention to the importance of frame to maximize the benefits of the progressive lens.
Acquisition of optometric degrees when buying glasses online
The degrees are mainly got from three places: physical store paid optometry data, hospital optometry data, previous degree (remember or retest). If you are in the hospital for optometry, it should be noted that there must be test glasses to try on, if there are no test glasses to try on, the data is not accurate.
