 |
|
30-07-2011, 12:30
|
#16
|
Registered User
Join Date: Dec 2005
Location: living aboard in Friday Harbor, WA
Boat: Vic Franck Delta 50
Posts: 699
|
there is an easy fix that I tested for a color blind friend a few years ago... small patches of Wratten filters affixed to glasses (red and green). I have some that I was thinking of productizing at one point... I'll dig it out (currently in the middle of a move) and see if I have enough to share with folks who need it.
Lights are easy to identify this way...
Steve
|
|
|
30-07-2011, 12:34
|
#17
|
cat herder, extreme blacksheep
Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 18,967
|
Re: Colour Blindness and Certification
sailed with a colorblind sailor for nearly a yr-- he did ok as the buoys are different shapes--yes he did require some aid in darkness as red lighted buoys are difficult to see even by those of us with intact color vision-- but we only hit the hard one time in a near year.
|
|
|
30-07-2011, 12:48
|
#18
|
Marine Service Provider
Join Date: Aug 2010
Location: north carolina
Boat: command yachtsdouglas32
Posts: 3,113
|
Re: Colour Blindness and Certification
have them memorize the sequences of numbers if its the splotch test or the lanturn test, thats the way I have seen it done ...ie. artificial means ...red and green means severe color blindness.Ive heard people say that color blindness means you only see black and white,thats silly.DVC
|
|
|
30-07-2011, 12:54
|
#19
|
cat herder, extreme blacksheep
Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 18,967
|
Re: Colour Blindness and Certification
guy i sailed with says he sees the lights, but not the colors -- the shapes delineate the kinds of markers they are-
|
|
|
30-07-2011, 13:53
|
#20
|
Moderator Emeritus

Join Date: Sep 2006
Posts: 4,663
|
Re: Colour Blindness and Certification
I'm red/green color deficient. I can differentiate them when they're bright, but when they're dim and/or small I can't tell green from white (or red from some other colors). I've tried all the color-vision tests that could be used to qualify me for the USGC licenses, but I just can't do it. Bummer. I didn't even realize I had this problem until I was in high school. I've been sailing since I was six years old, and I'm not going to stop now -- fortunately for me I don't need the license. All in all, I feel I'm a reasonably safe sailor, and I try to make up for my color problems by paying more attention than many sailors I've seen. Binoculars help make the lights bigger and brighter, so this helps.
I have seen, in a British sailing magazine, a set of red and green filters that can be used to help the color-blind sailor tell red from green. Don't know if they are an appropriate way to pass the RYA test though. I'm pretty sure that the USCG testing doesn't allow them.
[I see that Microship has mentioned what are probably similar filters]
__________________
Paul Elliott, S/V VALIS - Pacific Seacraft 44 #16 - Friday Harbor, WA
www.sailvalis.com
|
|
|
30-07-2011, 14:13
|
#21
|
Moderator Emeritus

Join Date: Sep 2006
Posts: 4,663
|
Re: Colour Blindness and Certification
__________________
Paul Elliott, S/V VALIS - Pacific Seacraft 44 #16 - Friday Harbor, WA
www.sailvalis.com
|
|
|
30-07-2011, 15:50
|
#22
|
Registered User
Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
|
Re: Colour Blindness and Certification
I have no knowledge of optics beyond the layman level. I have learned a bit thru interest for medical purposes as referred to in my earlier post.
But we know that light, in the form of color, is only a frequency of ray.
Camera filters change these frequencies as does stage lighting.
There is a standing joke here, that if you sail westward in Bermuda's Dundonald Channel in the late afternoon, the port hand marks are casuarina green and the st/bd hand marks are sunset red. They disappear against the shoeside and oceanside background, unless you look for them thru red coated lens binocs.
City emergency vehicles are fitted with cameras that recognise red lights and change them to green.
3D glasses work on frequency rules, don't they?
How do YOU know that the shade of red you see is the same red that your crew sees?
__________________
so many projects--so little time !!
|
|
|
30-07-2011, 16:13
|
#23
|
Moderator Emeritus

Join Date: Sep 2006
Posts: 4,663
|
Re: Colour Blindness and Certification
Filters don't change frequencies, they attenuate some more than others. They can do this by absorption, reflection, or a combination of these two.
Also, the emergency vehicles don't look at the color of the traffic signals. They do put out a specific infrared signal that is picked up by detectors at the intersections (these detectors look like cameras). The detectors then control the signal lights accordingly.
But yes, perceived color is a function of the frequency of the light ray. We know that we are all responding to similar wavelengths (frequencies) in a similar way, but the question of how we actually perceive these colors leads deep into psychology, metaphysics, and ultimately insanity. I'm not going risk thinking about it!
__________________
Paul Elliott, S/V VALIS - Pacific Seacraft 44 #16 - Friday Harbor, WA
www.sailvalis.com
|
|
|
30-07-2011, 16:36
|
#24
|
Registered User
Join Date: Mar 2011
Posts: 24
|
Quote:
Originally Posted by Paul Elliott
|
Now that is what I call a really useful app. I am going to use this in my next class. Thanks .... It may not be a complete solution but it's definitely what I am looking for.
|
|
|
30-07-2011, 16:36
|
#25
|
Registered User
Join Date: Dec 2008
Location: St. Georges, Bda
Boat: Rhodes Reliant 41ft
Posts: 4,131
|
Re: Colour Blindness and Certification
Thanks Paul,
I CMA by saying that I am a Layman. 
If attenuate implies an alteration from original form, thats what I meant by change.
Having learned a bit about Lebers Congenital Amorosis and Optic Nerve Hypoplasia, I know that a color ain't necessarily the same thing to any two people.
This is just one of those subjects I find really interesting.
__________________
so many projects--so little time !!
|
|
|
30-07-2011, 16:57
|
#26
|
Moderator Emeritus
Join Date: Aug 2005
Location: Carlsbad, CA
Boat: 1976 Sabre 28-2
Posts: 7,505
|
Re: Colour Blindness and Certification
If this is for non commercial qualifications, see no reason that they can't pass the needs of the qualification by other than color identification of various aids. After all, that's the reason that the various aids have different shapes and/or light sequencing. I would expect some accomodation would have to be made if the test is computer generated for only those with normal color vision. Commerical licensing would be another story.
If this was the USA, think the Disability Act would lay you open for a law suit which would be messy and expensive.
__________________
Peter O.
'Ae'a, Pearson 35
'Ms American Pie', Sabre 28 Mark II
|
|
|
30-07-2011, 17:51
|
#27
|
Registered User
Join Date: Mar 2011
Posts: 24
|
Quote:
Originally Posted by roverhi
If this is for non commercial qualifications, see no reason that they can't pass the needs of the qualification by other than color identification of various aids. After all, that's the reason that the various aids have different shapes and/or light sequencing. I would expect some accomodation would have to be made if the test is computer generated for only those with normal color vision. Commerical licensing would be another story.
If this was the USA, think the Disability Act would lay you open for a law suit which would be messy and expensive.
|
Colour blindness is not classed as a disability in the UK AFAIK. But it's an interesting thought.
|
|
|
30-07-2011, 18:07
|
#28
|
cat herder, extreme blacksheep
Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 18,967
|
Re: Colour Blindness and Certification
my friend i sailed with for a near year said all reds and blues and greens were same shade of grey. proved it by buyin ga lovely lightpurple fishin g rod n reel he thought was blue. he said it was grey so had to have been blue..
|
|
|
30-07-2011, 23:48
|
#29
|
Registered User
Join Date: Jul 2011
Boat: Bavaria 47
Posts: 172
|
Re: Colour Blindness and Certification
Surely everyone is colour blind at night, until there is enough light to stimulate the cones in the eye? I certainly have difficulty distinguishing between red and green lights until they are close, and I know I'm not colour blind as I have been regularly tested.
__________________
Nigel
Got a Bavaria? Want a Bavaria Forum? Click here!
|
|
|
31-07-2011, 00:13
|
#30
|
Registered User
Join Date: Dec 2009
Posts: 2,959
|
Re: Colour Blindness and Certification
If you cannot determine what a lit object is or it's relative heading you are obliged to give way...stay clear, no? So it's not a problem: the colour blind skipper gives way. As for collision avoidance: one should not rely on coloured side lights alone.
|
|
|
 |
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|