局部点药是眼部用药最常见的方式，但一般药物通过角膜困难，药物生物利用度低。纳米载体药物于8 0年代开始用于眼部，脂质体和类脂质囊泡(niosomes)与眼表的黏蛋白相互作用，延长药物在眼表的停留时间。纳米乳剂(nanoemulsion)的表面活性剂可以松解角膜上皮细胞紧密连接，形成转运开口，抑制细胞表面糖蛋白酶P(glycoprotein P，Pgp)降解药物活性蛋白。纳米粒子(nanoparticles)通过角膜上皮和结膜上皮而不会引起毒性。纳米胶囊(nanocapsules)更深地内化到角膜上皮(50 μm处)。聚合物胶束(polymeric micelles)自组装成核-壳纳米载体增强药物渗透角膜的能力。阴离子高代聚酰氨基胺(poly-amidoamine，PAMAM)树枝状大分子增强药物通透性，中性和阳离子低代树枝状大分子通过网格蛋白途径介导药物更高的通透性。纳米晶体(nanocrystal)，除增强药物溶解度和溶解速率之外，它的高黏附能力帮助药物保留和渗透到眼组织中。纳米结构材料与干眼关联密切，为干眼的治疗、诊断提供手段。

Topical administration is the most common method of ocular medication, but it is generally difficult for the drug to pass through the cornea, and the bioavailability of the drug is low. Nanocarrier drugs were used in eyes in the 1980s, and liposomes and lipoids vesicles (Niosomes) interacted with ocular surface mucins to prolong  the residence time of the drug on the ocular surface. Nanoemulsion surfactants can release the tight junctions of corneal epithelial cells, form transport openings, and inhibit the degradation of pharmaceutically active proteins by cell surface glycoprotein P (Pgp). Nanoparticles pass through the corneal and conjunctival epithelium without causing toxicity. Nanocapsules internalize deeper into the corneal epithelium (at 50 μm). Polymeric micelles self-assemble into core-shell nanocarriers to enhance the ability of drugs to penetrate the cornea. Anionic high-generation poly-amidoamine (PAMAM) dendrimers enhance drug permeability. Neutral and cationic low-generation dendrimers mediate higher drug permeability through clathrin pathway. Nanocrystal, in addition to enhancing drug solubility and dissolution rate, its high adhesion ability helps drug retention and penetration into ocular tissues. Nanostructured materials are closely related to dry eye and provide a choice for the treatment and diagnosis of dry eye.