Lens choice affects how much light passes through, how the optic handles heat, and how long it stays clear. These are the common materials used in LED optics.
| Material | Transmission | Notes |
|---|---|---|
| PMMA (acrylic) | about 92% | Best clarity, lower heat and UV tolerance |
| Polycarbonate (PC) | 88 to 90% | Very tough, higher temp, can yellow under UV |
| Glass | 90 to 92% | Heat and UV stable, heavy and brittle |
| Silicone | 90%+ | Flexible, handles high heat near a COB |
Matching material to job
PMMA gives the cleanest optics for indoor fixtures but softens and yellows if run hot. Polycarbonate trades a little clarity for impact resistance and higher temperature tolerance.
Close to a hot COB array, silicone or glass primary optics hold up where acrylic would degrade. Outdoors, UV stability and impact rating drive the choice.
See the Optical Efficiency Table and the Bridgelux Vero Series.
Choosing a lens material
The optic in front of an LED shapes the beam but also absorbs some light and must survive heat over time. The two common materials are acrylic (PMMA) and polycarbonate (PC). Acrylic has excellent clarity and light transmission and resists yellowing, but is more brittle and less heat-tolerant. Polycarbonate is far more impact-resistant and handles higher temperatures — better for rugged, outdoor, or high-output fixtures — at slightly lower transmission and more tendency to yellow over the years unless UV-stabilized. Glass is the most heat- and scratch-resistant and stays clearest longest, but is heavy and can break. Match the material to the fixture’s heat, impact exposure, and clarity needs.