This is real working physically-correct fresnel lens. Can be used for photocamera, binoculars, microscope, smartphone, VR helmet, and other optical devices.
You can see on a 360°-turntable here an example of simplest working binoculars.
Both convex and concave versions with different variations, for most tasks and needs.
3 level of detail:
Low-Poly (for games and long-range background)
Mid-Poly (usable for most cases)
Hi-Poly (only "max" format, for extreme hi-res closeups)
Also Mid-Poly and Hi-Poly contains optional variant with chamfered edges, which looks more realistic in closeups, but it cost a twice higher polycount.
File formats: 3ds max (redshift, vray, scanline), fbx, obj
Native | 3ds Max 2014 3ds Max 2014 | Default Scanline 3ds Max 2014 | V-Ray 4.30 OBJ FBX