I - SPY

Sunday, March 30, 2008

TYPE OF COLOURBLINDNESS

The doctor explained to me the different types of colourblindness.

Many forms of so-called colorblindness are really natural variations in the proteins. Just as some people have brown or blue eyes, different people have different pigments in their L- and M- cones.

And therefore, there are differnt types of colourblindness namely ; Protanomalous or deuteranomalous

And different types causes diffrent visions

NORMAL

Proton (L cone)

Tritan( S cone)

Deutan (M cone)

I suffer from the Forth type of colourblindness hich explains why i dont see the colours on the traffic lights

Its dangerous but i can survive. I hope.

5:28 PM

Friday, March 21, 2008

GENETICS

I went to see the specialist today and he explained that colour blindness is mostly heritary
however, my parents don't suffer from it.

That aside, most kinds of congenital colorblindness are caused by defects in the X chromosome. Since females have two X chromosomes and males have an X chromosome and a Y chromosome, colorblindness is much more common in males: females must have defects in both chromosomes before they exhibit colorblindness.

Approximately 5% to 8% of the men and 0.5% of the women of the world are born colorblind. That's as high as one out of twelve men and one out of two hundred women. People who are protans (red weak) and deutans (green weak) comprise 99% of this group.

In most colorblindness, the person has a different mixture of cones from normal. The cone cells on the retina are the crucial physical components in seeing color. People with normal color perception have three different cones, each cone is tuned to perceive mostly either Long wavelengths (reddish), Middle wavelengths (greenish), or Short wavelengths (bluish), referred to as L-, M-, and S- cones. Our minds determine what "color" we are seeing by determining the ratio between signals from different types of cones. In people with colorblindness, either a type of cone is missing, or the cone has a different peak absorption from normal.

So i am a rare case. =( its sad nto to be able to appreciate colours like others. but oh well.

3:00 PM

Saturday, March 1, 2008

C O L O U R BLIND NESS!!!

i used to think that colourblindness is just viewing things in black and white like a black and white television.
Apparently its not the case. Such cases, are extremely rare.

Just today we were tested for colour blindness in school.
my results came out positive.

The nurses tested me with pseudo-isochromatic plates use printed dots of different chromaticity to produce patterns that can be identified as numbers, letters or shapes.

TEST A TEST B

TEST C TEST D

to determine which colour blindness deficientcy i suffered from, they carried on with another test procedure.

Step 1: A color vision test pattern for testing red/green deficiency starts from a random pattern of gray level dots.

Step 2: We now add a digit pattern which is defined by yellow/blue variation only. This pattern can be detected by any observer which is able to do yellow/blue discrimination. Since most people with red/green deficiency will be able to do yellow/blue discrimination they will be able to see the digit 5 in this test pattern.

Step 3: Now we add another digit pattern which is defined by red/green variation and is easier to see than the pattern defined by yellow/blue variation. Here is the pattern composed of the random brightness pattern and the red/green pattern:

Step 4: Finally we add all three components: the random brightness pattern, the yellow/blue pattern, and the red/green pattern. Observers with red/green deficiency will not be able to see the red/green pattern and base their response on the yellow/blue pattern only. Normal observers will see both the yellow/blue and the red/green pattern. Since the red/green pattern is stronger than the yellow/blue pattern the normal subject will base his or her judgment on the red/green pattern and see the digit 6.

STEP 1 STEP 2

STEP3 STEP4

Its really unfortunate that i have colourblindness
Afterall its more common in males then females

Regardless, I will find out about colour blindness another time from the specialist.

1:22 PM