Fresnel lens: Difference between revisions

With the popularization of VR and the commercialization of VR HMDs to the general public, Fresnel lenses have been integrated into some headsets to try to reduce their weight, thickness, and cost. The type of lens used in a VR headset is generally a factor that is overlooked when determining the HDMs’ quality. Virtual reality headset lenses are important to help the viewer focus on the display’s images at close distances. <ref name=”3”></ref> <ref name=”5”>Visbit Inc. A guide to 360º virtual reality: part 2 - headsets. Retrieved from https://medium.com/visbit/a-guide-to-360%C2%BA-virtual-reality-part-2-headsets-5167a0d0870f</ref>

The standard lens used in almost all mobile VR headsets is a singlet. Compared to a Fresnel lens, singlets are thicker, heavier, and curved. High-end headsets like the HTC Vice use Fresnel lenses. The Oculus Rift CV1 has hybrid Fresnel lenses. <ref name=”5”></ref> <ref name=”6”>VR Lens Lab (2016). How lenses for virtual reality headsets work. Retrieved from https://vr-lens-lab.com/lenses-for-virtual-reality-headsets/</ref>

The use of Fresnel lenses in VR is not without setbacks. Boger (2015) explains that “the main problem is what happens when light hits the ridges, those peaks in the lens that do not correspond to actual curvature in the original lens. When light hits these points it is scatted, and scattered light in an optical system reduces contrast. Thus, you will often see that a Fresnel lens produces a more “milky” image with lower contrast. The second problem is a more technical one – it is more difficult to simulate a Fresnel lens in an optical design software.” Creating a lens with many segments will lead to a sharper image, but light will be lost. Lenses with fewer segments will lose less light but the image produce will not be as sharp. <ref name=”3”></ref> <ref name=”6”></ref>