What are the characteristics of Fresnel lenses?
Thin and light: Fresnel lenses are significantly thinner and lighter than conventional lenses.
Efficient: capable of achieving similar optical performance (focusing or diverging light) as conventional lenses.
Low cost: low material usage and simple manufacturing process, suitable for mass production.
Flexible design: can be designed as a focusing lens, a dispersing lens or a complex optical element according to requirements.

Highly Recommended Optical Fresnel Lenses from Yutai Optics:
Optical Fresnel Lenses
Rectangular Fresnel Lenses
Round Fresnel Lenses
PIR Fresnel Lenses