Reading glasses lenses are commonly made from acrylic.
In the world of ready-made reading glasses, the lenses have become customarily made from a type of plastic known technically as poly methyl acrylate. This material is widely used due to its optical properties and suitability for mass production.
Interestingly, acrylic lenses share the same key optical characteristics as CR-39, another common lens material used in prescription eyewear.
Key Properties of Acrylic Lenses
According to technical specifications, acrylic (poly methyl acrylate) offers specific properties that make it suitable for vision correction lenses:
- Index of Refraction: 1.49
- Abbe Value: 58
These values determine how light bends as it passes through the lens and how the lens handles chromatic aberration (the dispersion of light into different colors), respectively. Having the same index and Abbe value as CR-39 suggests that, from a material standpoint, acrylic lenses should offer comparable clarity.
Why Acrylic is Common
The widespread use of acrylic in most ready-made reading glasses is likely due to factors such as cost-effectiveness, ease of manufacturing, and sufficient optical performance for the magnification needs of basic reading corrections.
Summary of Lens Material Property:
| Material | Technical Name | Customary in Reading Glasses? | Index of Refraction | Abbe Value |
|---|---|---|---|---|
| Acrylic | Poly methyl acrylate | Yes | 1.49 | 58 |
| CR-39 (Comparison from Ref) | N/A | (Same properties as Acrylic) | 1.49 | 58 |
Choosing reading glasses often involves considering factors like lens material, magnification power, and frame style. While acrylic is standard in ready-made options, other materials might be used in custom or higher-end reading glasses.
