Monocular colorblindness

M Bartos mab at
Tue Jul 12 08:23:35 EST 1994

Sorry to barge in on the discussion - I happened to be trawling the net
for other material and couldn't help but be interested in the subject
line so if I mention something which has been discussed already then
excuse me...

It is possible to have monocular colour-blindness but it is extremely
rare - and the gold standard for testing it I suspect would be to look
at the frequencies of light backscattered from a known source shone into
each eye. (The eye with the abberant line of retinal cones with
different pigment would have a different backscatter spectrum). 

A similar but totally different ;-) condition involves different
coloured iri? iridities? irises? typicaly a brown colour for one and a red
colour for another - but this is associated with no other defect..

The appearance of monocular colour anomally could be mimicked by
exposing one eye to a particularly strong image - try closing one eye
and pointing the other at a bright point on your monitor for a little
while, then look at another scene and alternate between one eye and the
other - this should give you slightly different colour images...

I hope there is something of interest to you in what I've said :-)

Incidentally if any of you on your wanderings finds a reference to
people with congenital absence of cones could they drop me a line...
I've got a bet on with an astronomer about a historical figure who saw
better images than any of his contemporaries :-)

Best regards,

Martin Bartos

M.Bartos at

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