1, tips for identifying poor quality glasses
①, check the surface of the lens : if the lens is inclined to the light, such as poor finish, poor polishing, spots, stones, stripes, bubbles, cracks inside the lens, it is inferior.
②, check lens thickness : the thickness of two lenses is different, the thickness of a single lens is uneven, and the edge is weak and rough, which is inferior.
③, check spectacle frame : if it is found that the surface of spectacle frame has no luster, scratches, bruises, corrosion, etc., or there is no printing code, specification, size, brand, grade and other words on the spectacle frame, or the metal frame has low strength, poor elasticity, poor combination, poor polishing, etc., it shall be regarded as inferior spectacles.
④, observe the trial wearing effect : if you feel dizzy and swollen, the observation object is fuzzy, and there is deformation, it must be inferior.
2, damage of inferior glasses to eyes
①, harm of inferior glasses to human body : inferior glasses not only fail to correct vision, but also may cause new ametropia.
②, poor quality of lenses : poor quality lenses are often accompanied by surface defects such as glare, spiral shape, scratch, stripe, etc., which can cause visual deformation, blur, dizziness, headache, nausea, etc.
③, inaccurate optometry : if the glasses do not meet people’s vision needs, it will directly hurt the patient, making the wearer feel a strong headache or discomfort.
④, lens optical center deviation : if the optical center of both eyes is not the same, there will be double images, which will cause eye muscle imbalance, resulting in visual fatigue, strabismus, amblyopia and other consequences.
⑤ and inferior color changing glasses lead to poor eyesight : inferior color changing glasses, sunglasses absorb a lot of visible light, but harmful ultraviolet rays can pass through.