Blue light blocking glasses lenses and common glasses lenses have different colors.
The real blue-light-blocking glasses should be yellow. Based on the primary principles of optics, the light reflected from the lens is the light that resists the same color as it. As the name indicates, blue light is to prevent the reflection of blue light. Remove blue light, and all the red, yellow, blue, and green in visible light is yellow.
Application of titanium alloy
Titanium alloy is mainly used in aircraft engine compressor parts, followed by rocket, missile, and high-speed aircraft structural parts.By the mid-1960s, titanium and its alloys were already in common industrial use, making electrodes for industrial electrolysis, condensers for power stations, heaters for petroleum refining and seawater desalination, and pollution control devices.Titanium and its alloys have become a kind of corrosion-resistant structural material.In addition, it is used to produce hydrogen storage materials and shape memory alloys.
Is It Bad to Wear Reading Glasses When You Have Perfect Vision?
Can reading glasses hurt your eyes? This section will answer this question. One of the most common reasons for people to wear reading glasses is to see things clearly. If you read a lot or perform other tasks at close range for long periods, your eyes may feel strained. In general, strained eyes with near vision are associated with farsightedness. However, you might have similar symptoms just by observing something up close for too long. For this reason, reading glasses may be helpful.
However, do reading glasses hurt your eyes? No, wearing reading glasses should not hurt your eyes, even if you don’t have any problems with your eyesight. Meanwhile, it may take some time to get used to the reading glasses.
How to know if lens is polarized?
Make use of LCD screens. Point the glasses horizontally at the LCD screen and then rotate them upward by 45 degrees clockwise. If it is a polarized lens, it will show a change in color deepening. If it does not change no matter how you rotate it, it is not a polarized lens. You can borrow another person's polarized lens or have previously worn a known true polarizer, and place it crossover with the new glasses you want to buy. At this time, you should see the object clearly from the crossover part with your eyes. Then cross the glasses vertically and horizontally, and at this point, the opposite object should not be visible from the intersection. If this condition is satisfied, it means that a true polarized lens is being tested.
Buy Prescription Glasses Online Step By Step
1. Before you can buy glasses online, you’ll need a current glasses prescription.
2. Select an online retailer, comparing online retailers like EyeBuyDirect and KOALAEYE until you find the best fit for your needs.
3. Shop for the perfect frames according to face shape, frame favorites, the budget, etc.
4. Once you’ve found your perfect frames, you’ll enter your eyeglasses prescription and pupillary distance to choose the lenses.
5. Read over the fine print on return/exchange policies and product warranties before you complete your order.
6. Having picked your perfect frames, entered your prescription information, added any lens coatings and upgrades, and checked your online retailer's warranty and return policy, it’s time to complete your order.
Does it matter if the glasses are damaged when mailing?
Many people think that the frame of glasses is slightly damaged and can be ignored, in their eyes, if the lens is fine, the glasses are OK to use. In the whole process of matching glasses, it is necessary to choose a regular lens organization. The lens should be suitable, and the choice of the frame is very particular. Once the frame is out of shape, it needs to be replaced, and if left unchecked, further damage to the eye is possible.
Types of Progressive Lenses
At the same time, there are different types of progressive lenses and they are standard PALs, short corridor PALs, computer PALs, and Reading PALs.
Standard PALs must fit your vision needs. They can be added to frames of your choice, but you need to ensure that the frames are the right width and height proportions to grant enough space for the gradient changes in the lens.
Short corridor PALs are made to fit into smaller frames so as to suit a wider range of eyewear styles.
Computer PALs are designed for computer users and other occupations that require strong intermediate and distance vision.
Reading PALs are designed for those who enjoy reading and they can opt for a pair of lenses with a larger close vision zone.
