The Glossary of Optical Terminology by Thomas K. Farrell is written by an optician for opticians. Although it contains some entries from ophthalmology, the book is weighted toward the terms relevant to optometrists and opticians. "Astigmatism" has 23 entries, occupying two pages; "bifocal" has 9 entries, some illustrated, occupying five pages; and "glaucoma" has 1 entry occupying one tenth of a page.
"... it all depends on their frame."
Consequently, the book's strength is its comprehensive coverage of terminology related to opticianry. Lens materials and styles as well as the instruments used to make and measure lenses are described and compared in detail. Historical information and brand names are included. For example:
Bifocal, Modern "Straight Across" Types: This group of lenses includes such brand names as American Optical Company's "Executive," Bausch and Lomb's "Dualens,"... They occupy an important position in the multifocal world.
Punktal lens: A lens patented in 1911