What Are Pinhole Glasses?
Pinhole glasses, also called stenopeic glasses, are plastic eyewear with hundreds of pinhole-sized perforations in place of lenses. Pinhole glasses are mostly used to improve refractive errors in the eye because they shield the eye from indirect rays of light which can distort vision. This would decrease the blur circle on the back of the retina.
What are the benefits of recycling old glasses?
Recycling old glasses contributes to sustainability and reduces waste. It is a way to give charity in addition to giving money. It can be able to teach children the importance and impact of philanthropy.
Can clear lenses be polarized?
At present, there are no clear polarized lenses. A polarized lens is a thin film vertically arranged with silicon crystal coating placed inside the lens, just like a shutter, which covers the parallel light and only allows the vertical light to pass through. In this way, the glare from all directions can be eliminated, so it is clear and comfortable to wear. Transparent polyamide, the material of nylon lens, is a new variety of polyamide. The material of the nylon lens is mainly transparent polyamide. Due to the effect of the light filter, only light from a specific direction is allowed to pass through the lens, which filters the dazzling light from the sun on the water, land, or snow very well. It can not only make the landscape soft, clear, and natural but protect the eyes to a certain extent.
How to buy prescription glasses online?
Go to the ophthalmology department of a regular hospital first, because you need to take a photo of your optometry sheet to the seller when buying glasses online. Accurate optometry is the first step in choosing the right glasses. After getting the prescription, we can choose the frames online. Various material frames have different properties. Some are light and some are tough. In short, each has its own characteristics. I can't say which one is better. According to your own needs and face shape, choose the suitable glasses frame. Next, choose lenses. There are mainly two types, spherical lens, and aspherical lens. The aspheric lens is better. Also, confirm what specific functions are needed, such as radiation protection, UV protection, etc. Finally, the seller will look at the data on the prescription. If your eyes have high astigmatism, you need to add money. Then take the payment and wait for your new glasses. It’s unbelievable that you can buy glasses online in just a few minutes. Buying eyeglasses online is fast and convenient.
How to Test Blue Light Glasses (Amber and Red Lenses)
This section will show you how to test blue light glasses with amber or red lenses.
1. The Black and Blue Squares Test
1. Prepare black and blue paper.
2. Wear your blue light glasses after sunset and check whether both paper appear black.
3. If they do not appear black, your blue light glasses can’t block all blue light.
2. RGB Color Chart Test
1. Prepare an RGB color chart as follows.
2. Wear your blue light block glasses and look at the chart.
3. After wearing blue light blocking glasses, if the B section becomes black and the G section becomes darken, it shows that your blue light glasses block blue light and some filter some green light.
4. The less bright the green circle with your blue light glasses, the better they are.
Besides the above ways, you can ask the professional optician to perform a professional blue light glasses test, which would be more reliable. After that, you can know whether your glasses work effectively to block blue light.
What’s more, if you want to purchase a pair of effective blue light blocking glasses, you can try Koalaeye Optical. It is cheap and provides free shipping services.
What is an MR lens?
MR is the brand name of optical lens raw materials produced by Mitsui Chemicals in Japan. MR series is available in three different refractive indices (1.60, 1.67, 1.74): MR-7, MR-8, MR-10, and MR-174. MR-7 and MR-10 have higher thermal deformation temperature and excellent dyeing, which are widely used in the field of sunglasses. MR-8 has the most balanced performance index and is suitable for the production of lenses of any strength. It has the highest market share in lens materials with a refractive index of 1.60. MR-174 is a high refractive index lens material, which is mainly used in the production of ultra-thin lenses.
Step-by-Step Glasses Size Guide
In this section, we will show you how to perform glasses measurements. But the first thing is to know what face shape you have. If you do not know, click here to have a check.
Then you need to know where to find the size measurement of your glasses. In general, you will find numbers that look like this 51-17-145 at the temples of your eyeglasses. Of course, these numbers come at different meanings.
The first number often refers to the lens width. Lens width is the horizontal diameter of the lens at its widest point. In optometry, another term is eye size.
The second number often means the bridge width. Bridge width is the part that joins the two lenses and sits over the nose. Some refer to this as the gap. The bridge width varies between 14 and 24 millimeters.
The third number often means the temple length. The temple is the arm that keeps the sunglasses on your face. That arm extends to the part that hangs on the ears. The length is usually 135, 140, or 145 millimeters.
Lens height measures the size of the lens vertically, that is from the top to the bottom of the lens. Although sizes may differ depending on the brand, the standard size is somewhere between 32 and 38 millimeters.
