PPT Ishihara

8/18/2019 PPT Ishihara

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BackgroundMost cases of colour vision deficiency are characterised by a red-green deficiency which can beclassed into two types;1.a protan type which may be absolute (protanopia) or partial (protanomalia)2.a deutan type which may be absolue (deuteranopia) or partial (deuteranomalia)•.In protanopia the visible range of the spectrum is shorter at the red end compared with that of the

normal, and that part of the spectrum that appears blue-green in the normal appears to those withprotanopia as grey.

•.In deuteranopia the part of the spectrum that appears to the normal as green appears as grey.Purple-red (the complimentary colour of green) also appears as grey.•.In protanomalia and deuteranomalia, no part of the spectrum appears as grey, however the part ofthe spectrum that appears to those with protanopia as grey will appear as a greyish indistinct colourto those with protanomalia and similarily, the part of the spectrum which appears grey to those with

deuteranopia will appear as an indistinct greyish colour to those with deuteranomalia. s a result of this red-green colour vision deficiencies show blue and yellow colours clearer than redand green colours.•.!hose who suffer from typical total colour blindness show a complete failure to discriminate anycolour variations, usually associated with impairment of central vision with photophobia andnystagmus.•."ith atypical total colour blindness, the sensitivity to red and green, as well as to yellow and blue isso low that only very clear colours may be perceived. !here are, however, no further abnormalities in

the visual functions.Images obtained from:

Tests for Colour Blindnessby

Dr. Shinobu IshiharaProfessor Emeritus of the University of Tokyo

anehara Shu!!an Co." #td Tokyo" yoto $%&'()


2/25

Plate 1

Both normal and those with all

colour vision deficiencies

should read the number 12.


3/25

Plate 2

Those with normal colour vision

should read the number 8.

Those with red-green colour

vision deficiencies should readthe number 3.

Total colour blindness should

not be able to read any numeral.


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Plate 3

ormal vision should read the number 2!.

"ed-green deficiencies should read thenumber #$.

Total colour blindness should not read any

numeral


5/25

Plate %ormal colour vision should read the number &.

"ed-'reen colour deficiencies should read thenumber 2.

Total colour blindness should not be able

toread any numeral.


6/25

Plate #

ormal colour vision should read the

number 3.

"ed-'reen deficiencies should read the

number &.

Total colour blindness should not be able

to read any numeral.


7/25

Plate $ormal colour vision should read the number

1&.

"ed-'reen deficiencies should read the

number 1#.

Total colour blindness should not be able to

read any numeral.


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Plate %

ormal colour vision should read

the number #%.

"ed-'reen colour deficiencies

should read the number 21.Total colour blindness should not

be able to read any numeral.


9/25

Plate &

ormal colour vision should read the number

(.

The ma)ority of those with colour visiondeficiencies cannot read this number or will

read it incorrectly.


10/25

Plate '

ormal colour vision should read the

number %&.

The ma)ority of those with colour visiondeficiencies cannot read this number or

will read it incorrectly.


11/25


12/25

Plate

ormal colour vision should read thenumber #.

Those with colour vision deficiencies

will not read this number or read it

incorrectly.


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Plate *

ormal colour vision should read thenumber 1(.

Those with colour vision deficiencies

will not read this number or read it

incorrectly.


14/25

Plate +

ormal colour vision will read the number#3.

Those with colour vision deficiencies should

nor be able to read this number or will read it

incorrectly.


15/25

Plate

ormal colour vision and those withtotal colour blindness should not be

able to read any number.

The ma)ority of those with red-green

deficiencies should read the number &.


16/25

Plate #

ormal colour vision and those with

total colour blindness should not beable to read any number.

The ma)ority of those with red-green

deficiencies should read the number

%&.


17/25

Plate $


2(.

*n +rotano+ia and strong +rotanomalia the

number ( is read and in mild +rotanomalia

both numerals are read but the number ( is

clearer than the number 2.

*n deuterano+ia and strong deuteranomalia

only the number 2 is read and in mild

deuteranomalia both the number 2 is clearerthan the number (.


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Plate %


%2.

*n +rotano+ia and strong +rotanomalia the

number 2 is read and in mild +rotanomalia both

numerals are read but the number 2 is clearer

than the number %.

*n deuterano+ia and strong deuteranomalia only

the number % is read and in mild deuteranomalia

both the number % is clearer than the number 2.


19/25

Plate &

The normal should trace along the

+ur+le and red lines between the two

,s.

*n +rotano+ia and strong +rotanomalia

only the +ur+le line is traced and in

mild +rotanomalia both lines can be

traced but the +ur+le line is easier to

follow.

*n deuterano+ia and strong

deuteranomalia only the red line is

traced and in mild deuteranomalia both

lines are traced but the red line is

easier to follow.


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Plate '

The ma)ority of those with red-

green colour blindness can tracethe winding line between the two

,s.

The ma)ority of those with normal

and total colour blindness are

unable to follow the line.


21/25

Plate *

ormal will trace the blue-green line

between the two ,s.

The ma)ority of those with colour vision

deficiencies will be unable to follow the

line or will follow a line different to the

normal one.


22/25

Plate *

ormal will trace the orange line

between the two ,s.

The ma)ority of those with colour visiondeficiencies will be unable to follow the

line or will follow a line different to the

normal one.


23/25

Plate **

ormal should trace the line

connecting the blue-green and

the yellow-green.

Those with red-green

deficiencies trace the line

connecting the blue-green and

+ur+le.

Those with total colour

blindness cannot trace any

line.


24/25

Plate *+

ormal should trace the line connecting

the +ur+le and the orange between the two

,s."ed-green deficiencies should trace the

line connecting the +ur+le and the blue-

green.

Total colour blindness and weakness

cannot trace any line.


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Plate *

Both normal and those with colourvision deficiencies can trace the

winding line between the two ,s.

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PPT Ishihara