Re: Grayscale filters and low vision

Talked to a low vision researcher about this...

Dear All:

As you know there is very little research on color and reading - either
print media or monitor.  Way back in the 90s there was some work done on
color overlays for CCTV monitors, but no real consensus on whether any
helped or not.  One problem was in using overlays is that they reduce light
output as well as change the color with some overlays reducing light more
than others.  There have been a few studies that are suggestive and the
following is my view of where we are.  Please note that my view may not be
the view of “reality”.

Recent research has shown that changing brightness can improve visual
acuity (equivalent to up to 2 lines on the chart) and that changing color
temperature can independently (of brightness) further improve acuity.
These results seem to hold for both high and low contrast text.  The data
indicates that brightness and color temperature vary from individual to
individual suggesting that measuring illumination preferences would be
helpful in prescribing lighting for each individual.  It also indicated
that while some retinal diseases (i.e., macular degeneration) generally
require more light than others that there are exceptions.  In short, many,
but not all AMD patients benefit from more light.

We’ve recently shown that given the ability to alter the color of light
illuminating text that normally sighted individuals have better perceived
acuity.  The data (on 40 individuals) indicated that color preference was
very individual.  Most preferred a light that would be described as a shade
of green, although a few preferred light more in the yellow/orange shades.
So while the colors the normals chose didn’t match Chrissy’s preference,
the fact that they were very individualized suggests that she is correct in
selecting what works for her.

One obvious problem is how do you select the best color for the
individual.  While trial and error is tiresome it may be the current best
option for computer monitors.  In the long term having more systematic
research may reveal a better method.

On Fri, Jun 9, 2017 at 9:00 PM, Jonathan Avila <jon.avila@ssbbartgroup.com>
wrote:

> iOS 10 contains color filters – one of which is for grayscale.  I had
> someone ask if grayscale filters benefit people with low vision.    Do they
> help people with any of the areas listed in our document such with light
> sensitivity, contrast sensitivity, color perception, etc.?  Or is grayscale
> more of a diagnostic test filter or a novelty hat doesn’t actually make
> content easier to read for people with low vision or color perception
> disabilities?
>
>
>
> Best Regards,
>
>
>
> Jonathan
>
>
>



-- 
Jim Allan, Accessibility Coordinator
Texas School for the Blind and Visually Impaired
1100 W. 45th St., Austin, Texas 78756
voice 512.206.9315    fax: 512.206.9264  http://www.tsbvi.edu/
"We shape our tools and thereafter our tools shape us." McLuhan, 1964