The hazards of rusty spectacle frames
The most common allergenic metal is nickel. Once allergy occurs, it can cause contact dermatitides such as redness, swelling, itching, and yellow water on the surrounding skin. Many alloy products in daily life contain nickel, such as coins, various alloy products, electroplated objects, spectacle frames, metal watchbands, belt buckles, artificial jewelry, underwear buckles, etc. Their direct contact with the skin will cause allergies to sensitive people. Therefore, the temples and nose pads are the parts that contact the skin with a larger area. In particular, the outer surface of the metal frame and the metal contain a large amount of nickel, which can cause rust spots and skin corrosion, and allergies through contact with the skin and the erosion of sweat.
The weight difference between pure titanium frames and titanium frames
Titanium frames are slightly heavier than pure titanium frames, but they are both high-quality materials, so they are more comfortable on the outside. The specific gravity of pure titanium is generally 4.5, while titanium alloy is 8.9, which means the material is equivalent to half of the titanium alloy. So the frames are lighter in your hand.
What characteristics do children's glasses have?
The lens degrees need to change with the degrees of the eye. Because children are still in the process of growth and development, especially preschool children and adolescent children. Preschool is the key period of visual development, and farsightedness is slowly reduced. The eyeball development is close to an adult. Adolescence is the second peak of eyeball development, and myopia is most in this stage and little by little deepens, stopping at the end of adolescence.
Costs are lower for online stores.
The most fundamental reason is cost. The cost is not just the cost of the glasses, and there are many other aspects of the cost. If it is an online store, it only needs a warehouse, a computer, a customer service, which can meet the needs. And if it has the factory direct sales, then the product purchase cost is lower. The online shop needs publicity fees. For a physical store, the superior location, high rent, water, electricity, and labor costs, a variety of optometry processing instruments are valuable. There is a lot of brand publicity, decoration costs. These aspects are the cost of physical stores to pay.
Compared with single vision glasses, bifocals are multi-focal glasses.
Compared with single vision glasses, bifocal glasses, trifocal glasses belong to multi-focus glasses, and the types of trifocal glasses are diverse. When choosing the optical properties of a trifocal lens, it can be thought that the lens is made up of three different lenses: the main lens, the distal optic regions, two appendages. One for the distance and one for the proximal area.
Eyebrow frame
Just like an eyebrow, the big feature of the eyebrow frame is that the lines are relatively smooth, with curved radian like women's eyebrows, ergonomic, which can effectively reduce the pressure on the face of the glasses frame. And the design of the eyebrow line frame is beautiful and delicate, smooth and free, bringing you a cool visual experience.
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.
