>Does anyone know if research has been conducted to look at variations in
>nystgamus (gain etc) due to varying subject acuity? Do people think there
>might be differences?
We have computed a relation between nystagmus waveform and visual acuity,
called the "Nystagmus Acuity Function" or NAF.
See "The effects of afferent stimulation on congenital nystagmus foveation
periods" by Sheth et al., in Vision Research, vol 35 (1995), p 2371-2382.
Basically, acuity can be estimated by calculating foveation duration and
standard deviation. (We are interested in duration, reliability and
repeatability.) This measure is good, however, only for subjects who can
maintain accurate foveation, i.e. ±0.5° by ±4.0°/sec.
For those who can not hold their gaze that accurately, we are working on an
expanded NAF (NAFX), presented at ARVO in 1998. See "An expanded nystagmus
acuity function" by Jacobs et al., in the IOVS abstract program (S149).
Here, we have computationally expanded the foveation limits, allowing for
somewhat relaxed position and velocity criteria.
jon
Visit <http://www.evangelist.macaddict.com/>
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"Theory and practice are the same in theory, but different in practice."
Jonathan Jacobs Ocular Motility Lab (W151)
[log in to unmask] VA Medical Center
Dept. of Biomedical Engineering 10701 East Blvd.
Wickenden Building Cleveland, OH 44106
Case Western Reserve University (216) 421-3224, (216) 791-3800 x2500
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