Each spool has opaque material across both ends with a pinhole in each center. Viewing a distant light through the pinholes with the spool very close to your eye produces a nearly parallel light beam through your eye onto your retina. Red blood cells located directly in front of your retina diffract this parallel light, causing dark circle diffraction patterns on the retina.
These red blood cells sometimes cause floaters to appear in your eye when you stare into space, for example at the pure blue sky.
Demonstrate the optics of the eye and corrections of optical defects. Read More
Show inversion of the image on the retina by the eyelens. Read More
Model image inversion on the retina. Read More
Individual demonstration of image inversion on retina. Read More
See your retina! Read More
Identify nearsighted and farsighted eyes using laser speckle. Read More
Observe chromatic aberration in your eye. Read More
Show spherical aberration in eye and its correction. Read More
Demonstrate on-axis astigmatism. Read More
Demonstrate Mach bands. Read More
Demonstrate the dark axle illusion. Read More
Individual observation of floaters in the eye. Read More