1, comfortable choice
A) Super-vision reading glasses, only one pair is needed to see far and near, and the lenses are borderless and beautiful in appearance. Take into account the distance and reduce the burden on the eyes.
Disadvantages: the price is slightly higher, and it takes some time to adapt.
B) Double-light reading glasses can be observed from a long distance or from a short distance, but they are relatively vague in the middle distance and need an adaptation period. There are obvious gaps in different fields, objects jump and the appearance is not good.
Disadvantages: the interval between different areas is obvious, the appearance is ugly, and the middle distance is vague, so it needs to be adapted. There is jumping phenomenon, and you will feel dizzy when you go upstairs and downstairs.
C) Single reading glasses are "traditional reading glasses" with relatively simple functions. It's clearer when you look at nearby objects, and blurred when you look up from a distance.
Disadvantages: you can only look at it from a distance, not from a distance.
2. Selection of lens materials
A) Glass lenses have high hardness and good wear resistance. Generally, the quality and parameters do not change with time, but the impact resistance and weight of glass lenses are slightly worse than those of resin lenses.
B) Resin lenses are usually lighter than glass lenses and have better impact resistance than glass lenses, but their surface hardness is low and they are relatively easy to scratch. Resin lenses and coated lenses are soft because of their characteristics. Therefore, please be careful not to let the mirror directly contact hard objects. It is best to wash with water (or a small amount of detergent) before scrubbing, and then use special cloth or high-quality paper to remove water. In addition, coated lenses should be used with caution in poor environment to avoid dirt pollution.
3. Lens quality inspection
A) Hold your hand about 30 cm in front of your eyes and observe the distant scenery. The scene needs to be clear and without deformation, and there is no jump when moving slowly.
B) Lens: good light transmission, clear vision, no deformation, and no scratches and bubbles on the lens surface. From the side of the lens, it needs to be pure and bright, and the color is very clear; From the front, it needs good light transmission and no scratches; Inclined reflection requires uniform coating.
4. Glasses frame selection
The size and shape of the lens ring must be exactly the same, and the bridge of the nose is symmetrical;
The frame with smooth, fine and uniform material has good quality;
High-quality materials High-grade optical frames generally use high-quality materials such as memory titanium alloy and pure titanium.
Elastic frames are usually of good quality;
The frame with smooth and glossy coating has good quality;
Tight assembly of parts;
5. Quality inspection of spectacle frames
Wipe the metal frame gently with your nails to ensure that there are no scratches on the paint surface; The surface of the frame of the plastic plate does not need plastic particles, which is rough.
The welding position of the metal frame does not need obvious welding marks, no virtual welding, no fracture, etc.
The spectacle frame needs good flexibility, high adjustability and proper sealing.
Open and close the temple, feel the elasticity, and need to open and close smoothly.
The leaves of the spectacle frame should be symmetrical on both sides and fixed firmly.
6. Smoothness inspection: the frame is placed on the desktop, and the contacts are not suspended. If there are high and low sides, the specialist must adjust in front of the mirror to achieve a balance between the left and right.
7. Special material label: titanium is a precious metal, so the glasses frame containing this material will have corresponding marks on the temples: Ti-P/Ti-c: Ti is the symbol of titanium-containing material, Ti-P stands for pure titanium, and Ti-c stands for titanium alloy.