The thickness of tear film has been investigated under both invasive and non-invasive methods. While invasive methods are largely historical, more recent noninvasive methods are generally based on optical approaches that provide accurate, precise, and rapid measures. Optical microscopy, interferometry, and optical coherence tomography (OCT) have been developed to characterize the thickness of tear film or certain aspects of the tear film (e.g., the lipid layer). This review provides an in-depth overview on contemporary optical techniques used in studying the tear film, including both advantages and limitations of these approaches. It is anticipated that further developments of high-resolution OCT and other interferometric methods will enable a more accurate and precise measurement of the thickness of the tear film and its related dynamic properties.

泪膜的厚度已经在侵入性和非侵入性方法下进行了研究。尽管侵入性方法在很大程度上是历史性的，但较新的非侵入性方法通常基于光学方法，该方法可提供准确，精确和快速的措施。已经开发了光学显微镜，干涉术和光学相干断层扫描（OCT）以表征泪膜的厚度或泪膜的某些方面（例如，脂质层）。这篇评论提供了用于研究泪膜的当代光学技术的深入概述，包括这些方法的优点和局限性。