On an improved optometer for estimating the degree of astigmatism and other errors of refraction / by John Tweedy.

  • Tweedy, John, 1849-1924.
Date:
[1886]

Licence: Public Domain Mark

Credit: On an improved optometer for estimating the degree of astigmatism and other errors of refraction / by John Tweedy. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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