what is the average pd for a child? | KOALAEYE OPTICAL

what is the average pd for a child?

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.


Costco Optical

Costco Optical is staffed by highly trained opticians and is well known in the Optical industry. The Optics division also stocks a wide variety of contact lenses, brand name frames, and sunglasses, and provides the latest high-definition lens technology. Costco now accepts most vision plans.



Are night driving glasses good?

The color of night driving glasses can be selected from yellow to amber. Yellow lenses will reduce the light entering the eyes and reduce visibility. At night, this can be harmful. The lens filters out a lot of glare, but also filters out other visible light, making it difficult to see objects in dim or dark conditions.

Some people who wear night driving glasses say that they are more capable of seeing things at night. However, related test studies have shown that driving glasses at night does not improve night vision, nor can it help drivers see pedestrians faster than when they are not wearing glasses. A small study in 2019 showed that night driving glasses actually slow down the visual reflex by a fraction of a second, making night vision worse. So don't try to improve the safety of driving at night by wearing driving glasses with this kind of yellow lenses.

Does wearing sunglasses at night help driving? Like night driving glasses, sunglasses will reduce the amount of light entering the eyes, which makes them unsuitable for night driving and potentially dangerous.


Is it safe to buy contact lenses online?

Today's optometry is not a simple measurement of your degree. Through some professional instruments, they check the health of your eyes to see the health of your eyes. Is it appropriate to wear contact lenses at present? If there is inflammation in the eyes, it is forbidden to wear contact lenses, and if you wear them, it will cause harm to the eyes. If you buy online, you can't enjoy professional eye examination, try on, test, and other professional inspection and matching services that you can enjoy in professional stores, nor can you enjoy professional wearing and nursing guidance from professional staff. People often overlook eye problems that may result from the wrong choice of contact lenses, which are often overlooked by consumers.



When do you need prism glasses?

If you experience symptoms of headache, dizziness, and nausea, then these symptoms may be caused by a subtle disorder between the eyes. This situation is called Binocular Vision Dysfunction(BVD). Double vision occurs in the situation that light enters the eye at the wrong angle and sends two different images to the brain. Some people have diplopia, where they can see only one image, and flat images are often blurry. Prism glasses can help to change visual deformities. Prism lenses can be helpful to prevent myopia and farsightedness in both eyes. If vision deteriorates in one eye, the eye muscle can use an external corrective prism to prevent blindness. Standard glasses are made of a combination of prisms that can correct the focal length errors and corneal curvature. The prism moves the image up and down or left and right to form an overall view.


What are the benefits of Silhouette?

The wonderful style suits both men and women. The glasses are made of strong, reliable, and not heavy metal. They adopt a screw-free design and high-quality process. The glasses are made of titanium alloy temples and are highly ergonomic. They are not heavy and elastic (only 1.8 grams in weight), independent of momentum changes and extreme gravity. The temples and nose pads are made of hypoallergenic titanium alloy. With no screws and hinges, they provide optimal safety in space conditions.


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PRiSMA blue light blocking glasses

PRiSMA is a functional anti-blue light glasses brand introduced by Germany to the world. Since its establishment in 1993, PRiSMA has been selling well in 33 countries and regions around the world. They use OAR double-layer coating technology to reduce reflection and increase penetration index. Ensuring a high blue light barrier at the same time, they increase the color contrast, so you can see more clearly, and effectively relieve eye fatigue. The product can protect the retina and relieve visual fatigue. They regulate melatonin secretion or reduces visual stress.

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