偏光鏡是根據光線的偏振原理制造。是利用偏振光的特性，以偏振鏡片把非金屬物體、水面等反光過濾消除的透鏡。偏振鏡可以消除反光及使色彩更鮮艷，一些電影甚至全片用偏振鏡拍攝，使畫面有更濃艷的色彩。當陽光投射在路面或水面上時，直接刺激眼睛，使眼睛感到眩目、疲勞、不能持久視物。特別是當您在駕駛汽車、進行戶外娛樂活動時，不僅影響我們的工作和娛樂情緒，甚至影響我們對物象的判斷力而造成危險；長期經受陽光的直接照射，還會導致視力的急速下降，形成近視、遠視、散光或白內障等。這時候偏光鏡的作用就體現了。

偏(pian)(pian)光(guang)(guang)(guang)鏡(jing)(jing)片(pian)(pian)是采用(yong)和(he)隱形(xing)眼(yan)鏡(jing)(jing)一(yi)樣(yang)輕巧精密的(de)(de)(de)(de)合(he)成(cheng)樹脂制成(cheng)，制成(cheng)后，可(ke)濾去因水面潮濕或陽(yang)(yang)光(guang)(guang)(guang)照射下的(de)(de)(de)(de)馬(ma)路反(fan)光(guang)(guang)(guang)。主要(yao)優點：輕，能濾去99%刺(ci)眼(yan)的(de)(de)(de)(de)反(fan)射亂光(guang)(guang)(guang)，99%的(de)(de)(de)(de)有害(hai)紫外(wai)(wai)光(guang)(guang)(guang)，不(bu)易(yi)碎(sui)。為了過濾太(tai)陽(yang)(yang)照在水面、陸(lu)地(di)或雪地(di)上(shang)的(de)(de)(de)(de)平等方向的(de)(de)(de)(de)刺(ci)眼(yan)光(guang)(guang)(guang)線(xian)(xian)，在鏡(jing)(jing)片(pian)(pian)上(shang)加入(ru)垂(chui)直向的(de)(de)(de)(de)特殊涂料，就稱為偏(pian)(pian)光(guang)(guang)(guang)鏡(jing)(jing)片(pian)(pian)。最(zui)適合(he)戶外(wai)(wai)運動（例如(ru)：駕駛(shi)、海(hai)上(shang)活(huo)動、滑雪或釣魚）時使用(yong)。所以偏(pian)(pian)光(guang)(guang)(guang)太(tai)陽(yang)(yang)鏡(jing)(jing)可(ke)根(gen)據用(yong)途一(yi)般可(ke)以分為：滑雪鏡(jing)(jing)，釣魚鏡(jing)(jing)，偏(pian)(pian)光(guang)(guang)(guang)駕駛(shi)鏡(jing)(jing)，戶外(wai)(wai)運動鏡(jing)(jing)，高爾夫眼(yan)鏡(jing)(jing)。由于偏(pian)(pian)光(guang)(guang)(guang)太(tai)陽(yang)(yang)鏡(jing)(jing)的(de)(de)(de)(de)首要(yao)功(gong)能是防紫外(wai)(wai)線(xian)(xian)和(he)過濾偏(pian)(pian)振光(guang)(guang)(guang)，好(hao)的(de)(de)(de)(de)偏(pian)(pian)光(guang)(guang)(guang)太(tai)陽(yang)(yang)鏡(jing)(jing)鏡(jing)(jing)片(pian)(pian)可(ke)以阻擋(dang)90%以上(shang)紫外(wai)(wai)線(xian)(xian)的(de)(de)(de)(de)穿透，請(qing)選擇帶有“UV400”最(zui)佳阻隔紫外(wai)(wai)線(xian)(xian)標識(shi)的(de)(de)(de)(de)偏(pian)(pian)光(guang)(guang)(guang)太(tai)陽(yang)(yang)鏡(jing)(jing)；如(ru)果佩戴了不(bu)能阻擋(dang)紫外(wai)(wai)線(xian)(xian)和(he)偏(pian)(pian)振濾光(guang)(guang)(guang)功(gong)能的(de)(de)(de)(de)劣質偏(pian)(pian)光(guang)(guang)(guang)太(tai)陽(yang)(yang)鏡(jing)(jing)，比如(ru)深色的(de)(de)(de)(de)太(tai)陽(yang)(yang)鏡(jing)(jing)，隨著進(jin)入(ru)人眼(yan)的(de)(de)(de)(de)光(guang)(guang)(guang)線(xian)(xian)變暗，人眼(yan)的(de)(de)(de)(de)瞳孔會(hui)變大(da)，則進(jin)入(ru)眼(yan)睛的(de)(de)(de)(de)紫外(wai)(wai)線(xian)(xian)增加，增加對人眼(yan)的(de)(de)(de)(de)傷害(hai)。