Glass Lens's History

Question 1

1200
Flat Lenses

Answer 1

> 1200-1800. Actually lentil shaped
Clear central vision & poor peripheral vision

Question 2

1800
Periscopic Lenses

Answer 2

1800. Peripheral vision improved

-1.25 D back surface
was used

Question 3

1890
Six-base Meniscus Lenses

Answer 3

1890. Quality & peripheral vision markedly improved

Fit closer to the eye

Used until 1960

Question 4

1908
Punktal Lenses

Answer 4

Early 1900.
Carl Zeiss Punktal Lenses corrected oblique peripheral astigmatism

Required a large base curve

Question 5

1919
Corrected Curve Series Lenses

Answer 5

1919. American Optical Corrected Curve Series Lenses

Base curve 1-2 D intervals

Stocking of semi-finished lenses became practicable

Question 6

Aspherics

Answer 6

Early 1900. Lenses for very high + aphakia correction

Late 1900. High-index plastic lenses for + aphakic glasses

Question 7

Atorics

Answer 7

In 2000. New lines of Single-vision Finished Lenses, rapidly replacing the Aspheric Lenses Series

Generally, not available in multifocal lenses except for custom-made progressive lenses

Question 8

1960 Transiton + to -

Answer 8

1960, the transition from “+” front surface cyl form to “-“ back surface cyl form