Selected unworked slab of calculated lower density

Selected unworked slab of calculated lower density, free from infections, stage in the manufacture of 'Kryptok' bi-focal spectacle lenses.

Details

Category:
Optics
Object Number:
1921-323/54
Measurements:
overall: 50 x 50 mm
type:
ophthalmic lens
credit:
Dunscombe collection of spectacles