How do bifocal reading glasses work?
Bifocal reading glasses have two different lenses on the same lens. The top of the lens is your normal distance prescription, while the bottom is for close-up viewings, like reading. The two lenses allow you to alternate between them by moving your eyes up and down as needed. A bifocal lens is a type of lens that has two different areas of vision: one for close range and one for long-range. Typically, the upper section covers remote vision and the lower section covers reading. With a traditional bifocal lens, you can see the difference between the two lenses because the lower curve is a little different.
The Cons of Rimless Glasses
As there is no frame around your glasses lenses, the rimless glasses may be more likely to break. If you are not very careful with your glasses, you may have to replace them on a constant basis.
Rimless glasses are higher than other framed glasses because of the details that go into this style. In fact, the rimless style needs more work and time. So, making this kind of style is more time-consuming. So, rimless glasses are expensive than framed glasses.
From the above information, if you like rimless glasses, you can try them. Thus, you can buy them from Koalaeye Optical, which is an online store and provides all kinds of glasses, sunglasses, and frames. So, try Koalaeye glasses and the glasses will be mailed for you with your great convenience.
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.
The taboos of wearing glasses while driving at night
Night driving members should not wear tawny, green, and gray glasses. Tawny glasses can filter out most of the ultraviolet rays, although can make our eyes feel relaxed but easy to make people sleepy. Green glasses will turn red lights into black, directly affecting our judgment of traffic lights, so there is a great safety risk. Grey glasses, due to their low light transmittance, will weaken our line of sight and affect our observation of the road.
Different Types of Progressive Lenses
The first progressive lenses we want to introduce are computer progressive lenses, which are designed for clear vision in office settings. These lenses are ideal when using a computer for over 4 hours a day and help to reduce eye strain.
Computer progressive lenses are intended for indoor use and should not be worn over your regular glasses. The drawback to this is it requires you to have two separate pairs of eyeglasses.
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.
What Strength Reading Glasses Do I Need?
What strength reading glasses do I need? You can choose the reading glasses strengths by age or you can also perform a reading glasses test. If you are aging from 40 to 44, the +0.75 to +1.00 dioptre power is recommended. If you are aging from 45 to 49, the +1.00 to +1.50 dioptre is recommended. Age from 50-54, recommended power is +1.5 to +2.00 dioptre. Age from 55-59, recommended power is from +1.50 to +2.25 dioptre. Age from 61-65, recommended power is from +2.25 to +2.50 dioptre.
If you find two different strengths of reading glasses are available, choose the lower power because too strong strength can cause discomfort compared to weaker powered glasses and can even lead to nausea and dizziness.
So, if you need a pair of reading glasses, try Koalaeye Optical, which is an online glasses store. It provides all kinds of eyeglasses, sunglasses and frames. You can choose the satisfied one from here.
