This document discusses different types of lenses used in optometry. It describes how lenses are classified based on their material (glass or plastic), optical properties, and tints. Common materials used are discussed, along with their properties and any issues associated with high refractive errors. Additional lens designs like aspheric and lenticular lenses that help address problems with high prescriptions are also summarized. The document aims to provide an overview of decoding different lenses used in optometry.

1. Decoding the Lenses
Devanshi Dalal
Optometry Academic Incharge,
Choithram Netralaya,
Indore

2. • What is new about Lenses?
Which and when to consider!

3. Types of lenses !
Minus lenses plus lenses

5. How are lenses classified?
Lens Design
Lens
material
Lens Tint

6. Lens material
Glass
(Mineral) Plastic
(organic)

7. Properties of lens
Optical
properties
Mechanical
properties
Electrical
properties
Chemical
properties
Thermal
properties

9.  Optical properties
• Abbe value: measure of
dispersion
• Reflectance: reflections on
surface
• Absorption: % of light
absorbed
• Refractive index: ability to
bend light
 Mechanical properties
• Specific gravity:
• Impact resistance:
• Scratch resistance:

10.  Glass
• Crown glass
• Barium crown glass
• Flint glass
• High Index Glass
 Plastic
• CR- 39
• Polycarbonate
• Trivex
• MR- series
• NXT material

12. Problems with high refractive error
• Greater thickness
• Weight
• Aberration
• Magnification
• Visual field

15. Lens tint
Clear Tinted

16. • Filters – colored filters, coatings
• Photochromatic
• Polarized

19. Other designs for high prescriptions!
Lenticular
lenses
Aspheric
lenses

22. Aspheric lenses

23. Lenticular lenses

24. Lenticular lens in spectacle

25. Field of view with different designs

26. Acknowledgement
• I wish to acknowledge Choithram Netralaya
for conducting the session.
• I would like to thank
- Optom. Parth Vora ( Ami Optics plus)
- Mr. Nitin Artwani (Choithram Netralaya
Opticals)

27. Thank you