McCullough effect 
Author Message
 McCullough effect

I recently have heard of a move to use fewer green monitors and switch to amber  
ones because of the"McCullough effect". It has something to do with seeing pink  
images after looking at green. ? Could you explain what this actually is, and  
is there an actual hazard from green monitor useage?

 Bill

--  
Uucp: ...{gatech,ames,rutgers}!ncar!noao!asuvax!stjhmc!3600!3!Bill.Mathews



Mon, 19 Apr 1993 19:28:00 GMT
 McCullough effect
In a message of <20 Oct 89  19:35:33>, Bill Mathews (1:3600/3) writes:

 BM>I recently have heard of a move to use fewer green monitors and switch
 BM>to amber ones because of the"McCullough effect". It has something to do
 BM>with seeing pink images after looking at green. ? Could you explain
 BM>what this actually is, and is there an actual hazard from green monitor
 BM>useage?
 BM> Bill

I've not heard of the McCullough effect, but I have heard of "erythropsia"  
which is the pink afterimage after treatment with an Argon laser (which is  
green).  The green may be producing a problem either from that sort of  
phenomenon or possibly by stimulating the accomodative (focusing) mechanism of  
the eye producing low-grade ciliary muscle (focusing muscle) spasm and  
consequent headache.

Leo

210

--  
Uucp: ...{gatech,ames,rutgers}!ncar!noao!asuvax!stjhmc!14!Leo.Bores



Mon, 19 Apr 1993 19:38:00 GMT
 McCullough effect

Quote:
> BM>I recently have heard of a move to use fewer green monitors and switch
> BM>to amber ones because of the"McCullough effect". It has something to do
> BM>with seeing pink images after looking at green. ? Could you explain
> BM>what this actually is, and is there an actual hazard from green monitor
> BM>useage?
> BM> Bill

The McCullogh effect is a not-well-understood phenomenon of perception and
learning.  The effect is:

Look at horizontal stripes of black and green for a while ---several minutes
at least.  Then, if you look at vertical black and white stripes, the white
will look pink.  Unstriped white remains white.

(You could replace green with red & vice versa, same effect (its the
complementarity that matters).  You could replace horizontal with
vertical and vice versa too.)

What's neat / annoying is that the effect can last for days!!  And it can
be shown to be a cortical phenomenon, not retinal!

Please email me followups, I read this group sporadically.

--
David A Honig

Ceci n'est pas une .signature



Mon, 19 Apr 1993 22:57:00 GMT
 McCullough effect
#In a message of <20 Oct 89  19:35:33>, Bill Mathews (1:3600/3) writes:
#
# I recently have heard of a move to use fewer green monitors and switch
# to amber ones because of the"McCullough effect". It has something to do
# with seeing pink images after looking at green. ? Could you explain
# what this actually is, and is there an actual hazard from green monitor
# useage?
#  Bill

[Leo's response deleted]

When you stare long enough on something green and then move your eyes to
something white your eyes register a mix of white and absence of green
for a while.  This is pink.  The effect is harmless and sometimes called
an afterimage.  It has to do with decay time of chemicals released in the
retina. It typically lasts for a few seconds.  With an amber screen you
should get a bluish afterimage, but that is harder to see.

I don't know whether the McCollough effect is something else, though.

On the anecdote level, king Valdemar of Denmark was battling the Saxons
in year 1219 or so, and was staring on their shields which were green
with a black cross.  Then he looked at the sky, presumably for guidance
from above, and saw the afterimages all over the place.
And the Danish flag (red with a white cross) fell from the sky, as the
legend goes.



Mon, 19 Apr 1993 17:25:00 GMT
 
 [ 4 post ] 

 Relevant Pages 

1. McCullough Effect

2. McCullough Effect

3. Recent News About greenhouse effect. enhanced greenhouse effect,causes of greenhouse effect,greenhouse effect label diagram,explain greenhouse effect,demonstration of the greenhouse effect

4. starlix Tablets No Prescription!. starlix,starlix adverse effects,side effects of starlix,side effects of starlix medication,starlix side effects

5. Possible effects of ELF (was Re: Effects of RF energy)

6. Lariam effects/side-effects

7. Flagyl (metronidazole) side effects, adverse effects, adverse events, and adverse reactions

8. Effect of computer screens on eyes - Stereographic Effects?

9. All about pravachol!. pravachol side effects,side effects pravachol,side effect of taking pravachol,pravachol success stories,pravachol ezetrol

10. All about lexapro!. side effects of lexapro,side effects of drug lexapro,lexapro dosage,effects of lexapro,lexapro reviews


 
Powered by phpBB® Forum Software