Dictionary.com
definitions
  • synonyms

Masson disk

[mas-uh n]
See more synonyms on Thesaurus.com
noun
  1. a white disk on which a series of concentric gray circles appear to vanish intermittently when the disk is rotated, used for testing a person's fluctuation of attention and visual threshold.
Show More
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018