Different Type of Lenses: How to Choose
High-index lenses: These lenses are thinner and lighter than CR-39 plastic lenses because they have a higher index of refraction and may also have a lower specific gravity.
Trivex lenses: Trivex lenses are made from a newer plastic that’s similar to polycarbonate lenses. They are lightweight thin, and impact-resistant.
Aspheric lenses: Aspheric lenses have various degrees of curvature, which means they can be thinner and flatter so you can use a much larger portion of the surface.
Where can use the glasses emoji?
Glasses emojis are commonly used in glasses-related social media posts and are used to refer to things that have a point of view or demand only a little direction (for example, a museum exhibit, a movie, or a beautiful viewing platform). Although glasses have become a hot fashion accessory in recent decades, they still mean bookish or clever to a certain extent.
How to buy contact lenses online?
Choose a standard retailer. Contact lenses belong to three types of medical device products, and the sale of contact lenses and their care solution belongs to medical behavior. No matter it is an optical shop or contact lens e-commerce website, it must have a Medical Device Trading Permit before it can be sold. The trend of buying contact lenses online is obvious, and there are a lot of websites of individuals and contact lenses that do not have business licenses. Therefore when the user buys a contact lens on the net, be sure to look for management qualification of Medical Device Trading Permit, guard against being cheated.
How to Test Computer Glasses (Clear Glasses)
First, we will show you how to test computer glasses with clear glasses.
1. Ask for Blue Light Glasses Brand Spectrum Report
To find out whether your blue light glasses are the best computer glasses, you should contact the company you bought them from and ask for a spectrum report. It will show you how much blue light your computer glasses can block.
After sending the spectrum report to you, you should make sure that your computer glasses are able to filter at least 30% blue light, otherwise, they are unsafe.
2. Use the Lens Reflection Test
As for how to test computer glasses, you can use the lens reflection test. You can see what color the light is that reflecting off the lenses.
If it reflects the blue light, they are filtering some blue light. If the reflection is violent or purple, the computer glasses may be not effective.
This is a good way for you to perform a blue light test at home.
Why can't you wear expired contact lenses?
Contact lenses have a throwaway cycle. If the contact lens has been opened, the shelf life of the contact lens is calculated from the day it was opened. Contact lenses have a life cycle. The life cycle is the shelf life of contact lenses. For example, if you wear daily contact lenses, you will have to throw them away. If you wear monthly contact lenses, they will have a shelf life of one month. Even if you wear them only a few times, you will still have to throw them away. The shelf life of contact lenses is calculated from the day the lenses are taken apart, not from the number of days they have been worn.
After the shelf life of contact lenses, there will be some cases like lens aging, hardening, lens discoloration, decreased transparency, lens deformation, thickening, an increase of lens protein, and other precipitates. The microbe is easy to deposit, resulting in poor oxygen permeability. If you continue to wear it, it is easy to cause inflammation of the conjunctiva and corneal hypoxia, and the comfort level will be much worse. It is suggested to analyze the case according to your own care. Once the contact lenses have the above cases, they should be replaced in time.
Contact Lens Material - PHEMA material
It is the earliest material used in the production of contact lens hydrophilic material. The main advantage is water absorption, with a water content of about 38%. The material is soft, but its disadvantage is only partial oxygen permeability.
How to Remove Scratches from Prescription Glasses with Coating
It would be an unfortunate thing if there is a scratch on your prescription glasses. Some people may ask how to remove scratches from prescription glasses with coating. Unluckily, there is no magic cure to remove scratches from prescription glasses. Once your glasses are scratched, they are scratched.
However, there are some products on the market designed to make the scratches look less visible. In fact, most of these products are just waxy substances that wear off easily and they even can smear anti-reflective lenses.
So, if your glasses are scratched, for optimum vision and safety, you had better replace your lenses if they become scratched. When purchasing the glasses, you can go to the local optical store or choose online. For example, the Koalaeye Optical is a good choice because it is cheap and has free shipping. You can find some professional explanations on this website, such as Sphere, Cylinder, or Axis.
