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Plácido's disk

[plah-si-dohz]
noun Ophthalmology.
  1. a device marked with concentric black rings, used to detect corneal irregularities.

Origin of Plácido's disk

after A. Plácido da Costa (1848–1916), Portuguese ophthalmologist, who devised it
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
placido's disk in Medicine

Placido's disk

[plä-sē′dōz]
n.
  1. keratoscope
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.