Eyeglasses are mainly used to correct vision, and for children the purpose is to treat and restore visual function. As a result of bad quality glasses, the lighter the corrected vision is not ideal, the heavier the distorted vision, headaches, eye swelling, long-term wear will affect the recovery of children’s visual function and treatment of amblyopia. So many ophthalmologists believe that substandard glasses are as terrible as substandard drugs. Many people think: my frame is high quality, the lens is tested and qualified, then the assembled glasses must be qualified, in fact, this idea is wrong, just like a good material and stitching is not the same as necessarily get a fitted clothes. The main problem of assembling glasses is the assembly technology, mainly in the pupil and optical center does not match, astigmatism axial shift. The requirements of the frame: first of all, to meet the requirements of the optical center of the lens and the pupil center, but also requires a solid frame structure, the right size, wearing comfort with beautiful. Specifically: 1, can make the optical center of the spectacle lens and the patient’s pupil center distance equal, can make the lens optical center and the pupil center consistent. 2, the distance from the lens to the apex of the eye to 12 to 15 mm is appropriate, the distance is different will lead to the actual degree of change, myopic lenses from the eye the farther the degree of shallow, and for farsighted or presbyopic lenses, the farther the degree of higher, if the vision after wearing the lens is not as good as the same degree of lenses used in the trial, there is discomfort, to pay attention to whether such a situation. 3, so that the lens should be slightly downward tilt. Eyes flat or slightly downward gaze is the main, the glasses worn to tilt down about 10 degrees is appropriate, that is, the mirror and through the tangent of the cornea vertex into about 10 degrees angle. 4, glasses legs: length and curvature of the uncomfortable and too loose, glasses will easily fall off. Even damage to the glasses, too tight when pinching the ears, if children are children do not want to wear. 5, lid fissure should be located in the center of the frame. 6, try to choose a lighter frame, after wearing glasses should not be pressed head, nose. In addition, the entire color of the glasses should be suitable for the face color, hair color, clothing color, etc. as much as possible. The frame and face shape should match as much as possible to increase the beauty. Such as: oval face for ordinary type, can choose a variety of types of frames; long face optional horizontal line obvious thick and wide frame, do not choose no frame bottom edge or frame bottom is transparent frame; round face people frame position should be slightly up, the middle of the nose bridge a little higher, the frame should be a little thinner, in order to make the face slightly longer. The choice of lenses: glass lenses should be made of optical glass, optical glass has the advantages of stable refractive index, good uniformity, high light transmission. Good quality lenses with good transparency and finish, uniform texture, no hawk light, no streaks, no bubbles and particles in the center, diopter allowable error range: spherical lenses not more than 25 degrees, column lenses not more than 17 degrees, axial not more than 5 degrees. The technical department test qualified lenses can be used with confidence, but mastering some identification methods will help you to have a further understanding of the quality of eyeglass lenses. Should be so identify the quality of eyeglass lenses: two-handed frame, placed in front of the 25 to 30 cm, the lens convex outward, up and down slowly shaking, from the lens to observe distant objects. Look at the object like whether there are wavy irregular deformation or jump phenomenon, such as, known as “Huo light”, the lens surface is not flat. Lens finish: can be checked under an incandescent lamp, with a black screen as the background. The standard eyeglass lenses should be convex and concave. When you find a flat convex type of flower lenses or flat concave type of myopic lenses, you can basically conclude that they are made of flat window glass. In addition, window glass and other poor quality materials made of lenses, from the side of the view more green. Sunglasses are flat lenses, should not have a top focus. After wearing sunglasses, if dizziness, nausea and other symptoms of maladjustment, it is possible that the lenses appear top focus. Flat glasses after wearing the phenomenon of shifting objects, it is likely that the edge of the lens is not equal to the thickness of the cause. Identification of the quality of assembly of eyeglasses: the optical center of the lens and the patient’s pupil center should be the same. It is not enough that the distance between the two centers is equal, because there may also be a shift. The national standard stipulates that whether the assembled glasses are qualified or not is mainly determined by the five indicators: 1. top focus, 2. optical center horizontal deviation, 3. optical center vertical mutual difference, 4. optical center horizontal mutual difference, 5. astigmatism axial error. A pair of glasses if the above five items are qualified, then wear the lens optical center in the patient’s pupil center, can not meet these requirements of glasses is not qualified, this is very important, because myopic lenses are concave lens, the thinnest part of the optical center, and farsighted lenses and presbyopic lenses are convex lens, the thickest part of the optical center, if wearing glasses, optical center is not in the pupil center, there will be a trigeminal effect, the eye pain, eye swelling, headache. Eye pain, eye swelling, dizziness and eye fatigue, for adolescents, but also make myopia aggravated, children wearing such glasses for a long time will lead to amblyopia and strabismus, so the state regulations: the two horizontal error should not be greater than 2 mm, not allowed a high and a low, finished lenses optical center displacement allowed error range is: 300 degrees below, not more than 2 mm, 325 degrees to 600 degrees, not more than 1.5 mm The optical center of the finished lens can be shifted by no more than 2mm at 300 degrees and no more than 1.5mm at 325 degrees to 600 degrees. Many opticians do not pay enough attention to this, you can use the following method to determine the optical center of the glasses: on a piece of white paper, draw two cross-shaped straight lines more than 10 cm long, through the lens to see the cross line, move the lens, so that the line inside the mirror and the outside of the mirror line just connect into a straight line, at this time with a watercolor pencil on the lens tracing “cross” line, as The optical center of the lens is marked with a watercolor pencil. The easier way is to have the optician measure the optical center with a lens vertex meter and then mark it. After marking out the optical center and then put on the glasses, wear nearsighted glasses to look at the distance, wear presbyopic glasses to look at the near (about a foot away), then observe whether the optical center marked in the center of the pupil, if the deviation exceeds the error range allowed by the state for substandard products.