Do blue light glasses really protect your eyes?
Scientists at the University of Kansas in the United States summarized the results of studies around the world in the past 30 years and pointed out that there is not enough evidence in human trials to prove that blue light is related to macular degeneration, and there is no test showing that blocking blue light glasses are related to macular degeneration. Moreover, experts from the University of S?o Paulo in Brazil have observed after five years that patients who use anti-blue light intraocular lenses after cataract surgery have no difference in the incidence of macular disease compared with those who use ordinary intraocular lenses.
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.
Do blue light blocking glasses work?
Usually, blue light blocking glasses are yellowish, and this obvious color shift can cause serious visual fatigue. The aggravation of visual fatigue will not control myopia and will accelerate the progression of myopia. The most important thing is that some parents have the misconception that blue light blocking glasses can control myopia. If they allow children to use electronic products without guidance and control, myopia will definitely progress. During online classes, the best way to avoid the blue light damage of electronic products should be to relax their eyes between two classes. You can learn from the 20-20-20 rule recommended by the American Academy of Ophthalmology, which is to look at objects 20 feet away for at least 20 seconds for every 20 minutes. Also, you can take a break of 10-15 minutes between each online class. You can choose to look at the distance, play table tennis at home, or have fun with parent-child interaction. In this way, the tense shoulder and back muscles can be relaxed while the eyes are relaxed and rested. Not only can it prevent and control myopia, but it is also very helpful for improving the efficiency of learning. Teach children to blink their eyes more consciously when watching the electronic screen, and use a warm wet towel to heat the eyes during rest. A humidifier can be used at home to increase the humidity of the surrounding environment. This can effectively prevent dry eyes caused by looking at the electronic screens for a long time.
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.
Bifocal Lens
Bifocal lenses have two observation areas separated by visible lines, a larger observation distance area, and a smaller reading area. It may take some time for people who are wearing bifocal glasses for the first time to get used to the lenses. This is mainly due to learning how to move the eyes between the observation distance area and the reading area. Some people will also find that there will be an 'image jump' phenomenon at the visible line between the distance and the reading area, especially for those with limited mobility, who must look down when walking. The best way to get used to bifocals is to wear them as much as possible.
Is Anti Glare Worth It?
Is anti glare worth it? To answer this question, you need to know the benefits of the anti glare glasses first. Anti reflective coating and anti glare coating offer many benefits and are definitely worth the extra cost, especially if you find yourself bothered by glare. They can help you see better, look better and feel better.
Here, we will list some of the benefits of the anti reflective coating.
- They can improve your vision by reducing bothersome reflections and glare.
- They can also provide comfort during prolonged computer use as the glasses for computer use.
- They improve visual acuity by allowing more light to reach your eyes.
- They can reduce the effect and symptoms of digital eye strain.
- They make your eyes more visible behind your lenses.
- They provide less glare when driving at night.
So, is anti glare worth it? From the above information, you can find that anti glare glasses or anti reflective glasses are worth the cost.
Does it take time to get used to new prescription glasses?
People who wear new advanced glasses usually have an adjustment period. For novices, please gradually adapt to the glasses. In the first 2-3 weeks, increase the wearing time every day to adapt to the lens. For example, wear it for 1-2 hours on the first day, then add 2 hours a day until you feel comfortable. Before driving, please try it at home. Remember, you need to turn your head and move your eyes to find the 'sweet spot' for the activity you care about.
For experienced wearers, even under the same prescription, a new incremental pairing is required, and some adjustments are usually required. Progressive lens design, frame shape, and many other factors will also affect the adjustment time.
