Why Won'T The Screw On My Glasses Tighten? | KOALAEYE OPTICAL

Why Won'T The Screw On My Glasses Tighten?

How Long Does It Take to Get Used to Varifocals?

When you get a new pair of glasses, you have to get used to them. So, how long does it take to get used to the glasses? Some people only need a couple of days to get used to them while some others may need up to two weeks.

It is normal if you can only see the frame rim of your glasses when you first wear them. The reason for this lies in the brain’s visual center. It needs to adapt the new and greatly improved visual conditions.


The inadequacies of bifocals

The field of vision is smaller than that of the single vision lens, especially for the close view. For example, reading and reading newspapers need to make it coordinated with the head movement, there are optical defects of image jump and image displacement. There is a boundary, and it is easy to be seen that wearing a bifocal lens exposes age. Bifocals clearly demarcate the near and far regions, affecting appearance and vision. And when far view and close view change, the objects will jump. Because most myopic patients have a lag in the adjustment response, wearing bifocal lenses not only does not delay the development of myopia but has side effects. Therefore, bifocals are not suitable for teenagers to control myopia, and only a few special patients need to wear bifocals.



Types of Varifocal Lenses

As is well known, there are several types of varifocal lenses. So, in this section, we will list some the types of varifocal lenses.

Standard varifocal lens: standard varifocal lenses are the entry-level varifocal options and are chosen as an enhanced alternative to bifocals. They have clear and fairly wide focal areas for distance, reading, and in between.

Premium varifocal lens: premium varifocal lenses are also called free form varifocals or back surfaced digital varifocal lenses. It offers much clearer vision at all points and is a significant step up from a standard varifocal lens in terms of vision, clarity, focus, and ease of adapting to them. They are created using the latest computer-driven equipment and have a wider field of vision at the distance, intermediate/in-between, and reading focal points.


Can you buy prescription glasses for night driving?

Your eye doctor may prescribe special night driving glasses with an anti-reflective coating. AR coating helps reduce glare, improves vision, and helps you see better on the road at night. The lenses developed using wavefront diagnostics reduce halos, stellar bursts, glare, and other visual disturbances.



What Are Varifocal Glasses?

Varifocal glasses, also known as varifocals, varifocal lenses, PALs, or progressive lenses, have a gradual change in strength from the top of the lens to the bottom with multiple focal points in between. This allows you to see all distances and focus points through just one lens. Varifocal lenses are typically used when you have two prescriptions, one for distance and one for reading.

There are three regions of a varifocal lens which are distant zone, intermediate zone and, near/reading zone. Usually, the upper portion of the varifocal lens is the distant zone and the bottom portion of the varifocal lens is the near or reading zone.

One of the benefits of varifocal glasses is that you do not need to prepare 2 separate pairs of glasses or need to switch between frames for different vision needs.


What Glasses Lens Thickness Should I Choose?

In this section, we will show you how to choose glasses lens thickness. Lens thickness will depend on the strength of your prescription, your pupillary distance, the size of the frame and the lens material. Usually, high prescription glasses are thick.

If you have moderate nearsightedness, you should choose thinner lenses at the edge thickness of your lenses will be more visible. If your sphere prescription is between -2.50 and -4.00, the lenses with a refractive index of 1.6 would be an ideal choice. A lens with a refractive index of 1.67 is suitable for sphere prescription between -4.00 and -6.00, and any prescription over that a lens with a refractive index of 1.74 will be more suitable.

So, when you purchase prescription glasses, consider the glasses’ lens thickness also. If you want to get a pair of prescription glasses online, Koalaeye Optical is recommended. It is an online optical store and provides all kinds of eyeglasses, sunglasses and frames. Besides, these glasses are stylish and cheap. If you purchased, the glasses will be mailed to you with great convenience.


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Why should you clean the eyeglass case?

Although the eyeglasses case is used less, it can not be separated from the glasses. If it is not cleaned for a long time, it will affect appearance and carry a lot of bacteria.

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