Types of Adjustable Glasses
Adjustable glasses come in different types including adjustable reading glasses, adjustable focus glasses and adjustable focus reading glasses.
Adjustable reading glasses have an adjustable focal length and compensate for refractive errors. They provide variable focusing so you can adjustable them for desired distance and prescription. They are often used for reading because you do not need to adjust the position of your eyes.
Adjustable focus glasses offer an adjustable focal length. They are used to correct refractive errors including presbyopia. They provide variable focusing so as to adjust the glasses for seeing things close up or far away.
Adjustable focus reading glasses are the same as adjustable reading glasses. You can adjust the dials of the glasses so you do not need to reposition your eyes to see objects clearly in the near or far.
What Are Glasses Without Prescription?
Nowadays, some people wear glasses not only just for correcting their vision, but also for fashion. However, for those people who do not have any eye conditions such as nearsightedness, farsightedness or astigmatism, they can wear glasses without prescription.
Glasses without prescription, also called non-prescription glasses or clear lens glasses, work as a fashion statement to add style to your wardrobe. They also may serve a purpose if they have blue light blocking lenses.
Throughout the years, many people choose to wear glasses without prescription to improve their look. This trendy accessory is a reality available in a range of designs, colors and materials that can add just the right touch to your outfit.
It is important to note non-prescription glasses have zero corrective power whatsoever, while non-prescription reading glasses offer some level of magnification, enlarging what you see up-close.
What Is Plastic Lens?
In the above part, we have introduced what polycarbonate lenses are. In this section, we will show you what the plastic lens is.
The plastic lens was first introduced in 1947. Since then, plastic has become a popular and widely used material for making eyeglasses lenses. Since the introduction and use of plastic lenses, it has sealed its mark as the most preferred choice in the optical industry.
Plastic lenses are light. With this feature, plastic lenses are popular because they will not be heavy inside the glasses frame and permit for an easy fit in any type of glasses frame. In addition, plastic glasses are cheap and easy to obtain in desired amounts. So, they are affordable for most people. Plastic lenses are very durable. So, they do not shatter easily on impact which makes it a great choice for individuals who are active or tend to drop their glasses often.
However, compared with other lens materials, plastic lenses are usually thick due to their low index of refraction. The soft feature of plastic glasses makes them susceptible to scratching from a sharp object and why scratch-resistant coating is applied to form an additional protective layer. Plastic lenses do not provide ultraviolet protection.
To protect the lens.
Avoid getting chemicals on your glasses, and if you do, rinse with water immediately. If there is sweat and grease on the glasses, they should be washed to avoid corrosion. Do not use clothes or towels to wipe the lenses. Rubbing the lens with a rough cloth can cause scratches on the surface of the lens. So it is best to use special glasses cloth when you wipe the lenses, and when you wipe the glasses, you must hold the glasses on one side of the frame with your hand, and then gently wipe the glasses with the glasses cloth. Remember not to overexert, otherwise, it is easy to cause frame and lens damage.
3 Common Problems with Progressive Lenses
Though progressive lenses are popular to correct some eye conditions, there are also some drawbacks. So, in the following section, we will show you some common problems with progressive lenses.
Dizziness: the three different focal lengths of progressive lenses can make people susceptible to dizziness, as well as vertigo. From long to medium to short distance, the lenses offer a gradient of increasing strength. So, it would have trouble in adapting the glasses for the people who are wearing them for the first time. A common mistake is to look out of the wrong focal length, causing their vision to be blurry and lead to an overall feeling of dizziness.
Peripheral distortion: another common problem of progressive lenses is the way in which they blur peripheral vision. Most glasses cause an initial distortion to vision. However, the three different segments found in these lenses can make that distortion feel more prominent than other pairs of eyeglasses. And most people may need two weeks to adjust to progressive lenses.
Depth perception: Since progressive lenses provide three different prescriptions to see objects clearly for different distances, it is important that you need to move your head instead of your eyes when focusing on objects at different distances. Prior to adjusting to this little nuance, progressive lenses can cause depth perception to feel off.
From the above information, you have known some common problems with progressive lenses. So, you may ask how to adjust the progressive lenses. The most popular way is that you need to wear them frequently.
The Disadvantages of Trifocal Glasses
Here, we will show you the disadvantages of trifocal glasses. If you wear the trifocal glasses for the first time, you may spend some time getting used to them. Adjusting to wearing trifocal glasses can take some time. The different fields of vision can make them disorienting at first, but over time you will get used to wearing them and your eyes will naturally move to the prescription they need for the task at hand. You may be interested in this post: How Long Does It Take to Get Used to New Glasses?
Features of pure titanium glasses frame
Due to the lightweight (ordinary nickel-based alloy frame weight 48%-60%), high strength, corrosion resistance, surface easy coloring, beautiful and durable features of spectacle frame made of pure titanium, they have been loved by most consumers. But the elastic modulus of pure titanium is higher (about 120GPa). The temples of the frames made from them are not elastic enough. After wearing the glasses for a period of time, the temples of the glasses need to be adjusted due to the relaxation of the stress. The processing plasticity of titanium metal is worse than that of other metal materials, so the processing technology of its wire is difficult. The surface quality is difficult to control, and the technical content is high. The surface quality of pure titanium wire produced by a few domestic manufacturers is poor.