Short sight, long sight and astigmatism : an elementary guide to the refraction of the eye / by George Frederick Helm.
- Helm, George Frederick, 1838-1898.
- Date:
- 1886
Licence: Public Domain Mark
Credit: Short sight, long sight and astigmatism : an elementary guide to the refraction of the eye / by George Frederick Helm. Source: Wellcome Collection.
Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.
101/136 (page 89)