tear meniscus

(redirected from tear prism)

tear meniscus 

A thin strip of tear fluid with concave outer surfaces at the upper and lower lid margins. It contains most of the exposed tear volume. The absence of a tear meniscus is an indication of a dry eye. Syn. marginal tear strip; lacrimal prism; tear prism. See precorneal film; lacrimal lake.
References in periodicals archive ?
You can also assess tear breakup time (normal TBUT [greater than or equal to] 10 seconds+), tear prism regularity and height (normal height = 0.
Is the tear prism at the lower lid margin even and easily visible?
7) Most of this lies beneath the lids and in the tear prisms of tear fluid, with only 1-2[micro]l lying across the ocular surface.