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 To Do with Old Glasses?
What to do with old glasses? Where can I donate old glasses? You may have the same troubles. So, in this section, we will show you what you should do with your old glasses.
You can choose to donate your old glasses. Around the world, about 13 million children can’t finish their education for the sole reason that they can’t see well enough to learn. In addition, there are some goodwill organizations that will take your used reading glasses as long as they are in decent shape. So, what to do with old glasses, donate them. Where can I donate old glasses? You can search the old glasses donation organizations online.
If you have a pair of old glasses, you can also choose to sell them online to save some money. You can sell them on some platforms such as eBay or Preloved.
Should you choose titanium or pure titanium frames?
In reality, there is no absolute good or bad, if it is comfortable to wear, suitable for personal preference. They are good glasses for a single person, because if someone else wears the right and good-looking glasses, you may not wear the right and good-looking glasses yourself. Therefore, it is still a specific problem, with specific analysis, suitable for their own is good.
How do I choose the right glasses frames?
Choosing a frame is largely a matter of personal preference. However, in addition to the style, you need to check the comfort level to see if there are problems like ear clips, nose compression, skin irritation, and so on. Please note that if you are highly short-sighted, try full-frame glasses, because full-frame glasses can hold heavier lenses more reliably. Below are a few easy ways to determine which frames would best flatter your face and show off your style and personality.
Step 1: Identify your face shape. Identifying your face shape is a good place to start when it comes to learning how to select frames which will suit your face shape.
Step 2: Choose colors that complement your skin tone. If you have a cool-colored skin tone, opt for shades of black, gray, and blue. If your skin tone is warm, you would benefit from warm colors, such as tan, pink, and red. As always, when you learn how to select frames, it is easy to know which colors suit your skin.
Step 3: Consider your way of living. When considering how to select frames for your lifestyle, one of the most important things is to make sure the frames fit at the bridge of your nose. This will allow your glasses to stay put better. If you exercise often, comfortable, sturdy frames are a must. If you want to look the part at an important business meeting, you can choose stylish frames with a variety of angles. If you need sunglasses for the beach, go for soft, colorful frames that will complement your relaxed vibe.
Step 4: Flaunt your personality.Frames are the perfect way to show off who you are and your personality. In the process of learning how to select your frames, you cannot forget to choose those that show off your personal style. You can find the perfect shapes, colors, or patterns, but those qualities mean very little if you aren’t comfortable.
What should drivers notice when wearing polarized glasses?
Many drivers like to wear polarized lenses. Indeed, the polarized lens can reduce strong light, eliminate glare, so that the line of sight is natural and soft, but the polarized lens is more suitable for fishing, skiing, and other large areas of the reflective environment. Drivers sometimes have to face the tunnel and another dark scene, the polarized lens is easy to make people suddenly feel dark at the moment. In addition, polarized lenses can make LCD screens and LED traffic lights dim. Therefore, when choosing polarizers, it is best to choose good quality optics, and when going through the tunnel, it is best to take off your glasses ahead of time and blink a lot. Before wearing the driver polarizing lens, try it on and observe whether the polarizing film of the lens is smooth. If the polarizing film is uneven, there will be inflow in the imaging, which may lead to visual fatigue and migraine.
Optometry for prescription glasses
The key prerequisite for proper glasses is accurate optometry. In foreign countries, professional optometrists are generally required to be qualified to issue prescriptions for optometry. However, this is not very standardized in China. Many optometrists have only been trained for a short period of time and do not have the basic knowledge of ophthalmology. For some complex situations, they may not give a proper prescription for glasses. Therefore, optometry should choose a qualified institution. If you are adolescents, people with high myopia, people with anisometropia, etc., you may need to dilate your pupils for optometry. It is best to go to the optometry center of the hospital for optometry.
About the Glasses Direct
Glasses Direct is an online professional eyewear shopping site based in the UK, with the leading online sales volume in Europe. Over the past five years, its online sales have increased by 50%, and it has had more than a million customers. Since 2004, they have been providing affordable glasses with uncompromising quality and professional service. The frames selected included big brands like Ray-Ban and Oakley and came in a variety of shapes and sizes. Its main goal is to provide a convenient option for people who need corrective glasses.
