How to distinguish the harm of inferior glasses
4hw.com.cn: we all know that the glasses industry is a profiteering industry, which costs thousands of cheap ten yuan. Poor glasses do great harm to people's eyes, so how to distinguish them? Let's have a look.
Tips for identifying poor glasses
① . check the surface of the lens: the lens is inclined to the light. If the finish is poor, the polishing is not good, and there are spots, stones, stripes, bubbles, cracks, etc. inside the lens, it is a poor product.
② . check the thickness of the lens: the thickness of the two lenses is not the same, the thickness of the single lens is not uniform, and the edge is weak and rough, which is inferior.
③ . inspection of spectacle frame: if it is found that the surface of spectacle frame has no luster, scratches, bruises, corrosion, etc., or there is no printed code, specification, size, trademark, 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 effect of trial wearing: if you feel dizzy and distended, the observed object is fuzzy and deformed, it must be of poor quality.
2. Damage of poor glasses to eyes
① Harm of poor glasses to human body: poor 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 Huoguang, helix, scratch, stripe, etc., which will cause deformation and blurring of visual objects, making people feel dizzy, headache, nausea, etc.
③ Inaccurate optometry: if the glasses do not meet the needs of people's vision, they will directly hurt the patient, making the wearer feel a strong headache or discomfort.
④ . optical center deviation of lens: if the optical center of both eyes is different, double images will appear, which will cause the eye muscle to lose balance, resulting in visual fatigue, strabismus, amblyopia and other consequences.
⑤ Poor color changing mirror, resulting in poor vision: poor color changing mirror, sunglasses absorb a lot of visible light, while harmful ultraviolet rays to human eyes can penetrate.