Definition of twenty-twenty in English:

twenty-twenty

(also 20/20)

adjective

  • Denoting vision of normal sharpness.

    • ‘‘I took you to the optometrist and she said that you had perfect twenty-twenty vision… I don't understand machines these days… ‘she mumbled to herself and walked back out.’’
    • ‘They slowly faded into the lenses, leaving only crystalline images, better than twenty-twenty vision.’
    • ‘For example we could make sure they had something as simple as twenty-twenty vision, or something as complicated as great strength.’
    • ‘I guess my twenty-twenty eyesight went out with the lights.’
    • ‘It didn't take twenty-twenty vision to see the worry cross her features.’

Origin

The Snellen fraction for normal visual acuity (see Snellen test).

Pronunciation:

twenty-twenty

/ˌtwen(t)ēˈtwen(t)ē/