Discoloration time and fading time for color-changing lenses
In general, color-changing lenses take about 30 seconds to 1 minute to darken on average when exposed to sunlight/UV and will continue to darken for about 10 minutes to reach the lens depth of full-color sunglasses. Color-changing lenses of good quality and workmanship are restored to an almost clear and transparent state in 2 minutes and completely cleared in 5 minutes, although the high temperature can affect this. If you want to change a single color change lens, the color of the old and new lenses will be inconsistent. This is because the discoloration performance of the old lens will be reduced due to the long-term use of the discoloration agent. Therefore, in order to ensure the normal use and aesthetic appearance, it is usually recommended to replace the two lenses at the same time.
What glasses are best for night driving?
You had better not make myopia sunglasses directly with sunglasses frame. The radian of a lot of sunglasses is too high. When the nearsightedness lens that uses 400 degrees directly is squeezed into radian even 600 degrees to 800 degrees frame. The actual degree of the lens and other parameters will change. And, to meet the processing that sunglasses frame needs, the pupil distance of most myopic sunglasses was magnified 4 mm above. This is eye damage! No matter what style or look your glasses are, make sure they are specifically designed to eliminate glare and improve your view.
Sunglasses have a visible light transmittance of about 20% and can absorb ultraviolet and infrared rays well. It also has a variety of colors such as light green, light gray, light brown, etc., used to protect in different occasions. Among them, light gray lenses have little effect on color recognition. Light brown glasses make the blue sky look darker and reduce the transmission of green light. Light green lenses reduce the transmission of red light.
Sunglasses not only have a wide range of varieties, but with the improvement of decoration and health care effects, their scope of use has become more extensive. As the time to update sunglasses can be rapid, fashionable men and women would love to have multiple sunglasses to match clothes to satisfy their pursuit of fashion.
Why should children wear blue-light-blocking glasses?
Due to the short wavelength of blue light, the focus will fall in the front of the retina. In order to see clearly, the eyeball will be in a state of tension for a long time, causing visual fatigue. Studies have found that exposure to blue light at certain doses can damage epithelial cells on the surface of the eye, causing or aggravating dry eye. Harmful blue light has extremely high energy and can penetrate the lens directly to the retina, leading to the atrophy and death of retinal pigment epithelial cells. The death of light-sensitive cells will lead to vision loss.
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.
The characteristics of metal material
The material of metal glasses frame chooses some kind of metal material or alloy to make mostly. Most of the copper alloys are treated as the base material and then have surface treatment processing. Then there is the recent rise of pure titanium frames and those made of memory alloy. Metal frames are usually equipped with nose pads, which are movable to accommodate a variety of nasal shapes. The end of the temple is often covered with a plastic cover, not only beautiful but also to protect the temple and skin.
Westie Dog Eyeglass Holder
The spirit of Westie is captured by this adorable dog frame, which stands about 4.5 inches tall and can be fitted with glasses, sunglasses, and so on. This dog frame is a great choice for children's frames. It uses high-quality resin designed and manufactured in the UK. Each dog spectacle frame is hand-painted and comes in a gift box.