Motion Blur

[Joann Raytar]

I have one of those weird questions again. I just read the abstract "A Human's Eye View: Motion Blur and Frameless Rendering" by Ellen J. Scher Zagier. The basic concept here is to increase video quality by matching a camera's shutter speed to the human eye's.

One of the points she makes is that the human eye has a problem handling unpredictable motion, an inability to eye-track at the same rate as the motion and an inability to track an object moving in a different direction as the eye. Does anyone have a rough idea up to what speed the human eye can track without an object blurring? For example, when I wave a ruler back and forth rapidly it is obviously a predictable motion and my hand cannot be moving all that fast yet the ruler blurs.

Does the percieved motion of objects and our eyes ability to track objects have anything to do with the swim some folks encounter when wearing progressive lenses? I know there is a degree of surface astigmatism along the periphery but it must be our perception of motion through this area causing the problem.

[chip anderson]

That's aberration along the periphery.

[Joann Raytar]

Unfortunately, the superior optics and line-free nature of a PAL surface does have a bit of a price to pay... This change in curvature results in an inevitable consequence: surface astigmatism. Surface astigmatism produces an unwanted astigmatic error (or cylinder error) that can, in sufficient quantities, blur vision and limit the wearer’s field of clear vision. Therefore, this astigmatic error essentially serves as a boundary for the various zones on the progressive lens surface.
- from the web pageFundamentals of Progressive Addition Lens Design located in Sola Technical Articles
Darryl Meister, ABOM
SOLA Technical Marketing
Lens Talk
Vol. 26, No. 13 (Apr. 1998)

Chip, I meant astigmatism. ;)