. Refraction and how to refract : including sections on optics, retinoscopy, the fitting of spectacles and eye-glasses, -e O (39 X 30mm.) is the usual size for the average adult, and number2, 3, or 4 is for a child. C, D, or V may be ordered for a LENSES. 287 presbyope who docs not need a distance glass and whodocs not wish to be takingr off the near correction to see at. Fig. igo.

---

Size: 1742px × 1435px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ., bookcentury1900, bookdecade1900, bookidref, booksubjecteyeglasses