Ishihara's Tests for Colour Deficiency
Authentic and accurate images of Ishihara's test plates
Just because it's black in the dark,
Oh, doesn't mean there's no colors.
— Laleh (Colors)
Authentic and color-accurate images of Ishihara's test plates for colour deficiency.
I provide high-resolution bitmaps and SVG files for each plate. I also provide the position, size, and color of each circle on each test plate.
Can this information be used to make fakes? Yes, but at least they'll be really good ones. Also, please don't.
If you're interested to learn more about colorblindess and the mathematics behind it, see my Designing for Color Blindness, Palettes for Color Blindness and Math of Color Blindness.
And turn those lines of confusion into understanding!
Your Ishihara Tests for Color Deficiency book is probably a fake. The first one I bought certainly was.
If you bought it on Amazon, it's fake.
If you paid less than about 150 USD, it's fake.
If you didn't buy it from a legitimate seller of optometry or medical equipment, it's fake.
Real plates are perfectly 12 cm × 12 cm square and contain the plate index on all four sides of the circle (red arrows). The dot pattern is approximately centered on the plate. Your book should also have a certificate of authenticity.
Fakes will be low-effort and easy to spot — once you know what to look for.
My fake book came in a real cover (I still don't understand this) but all the test plates were fake. The book had a real manual but no certificate of authenticity.
The plates weren't square (11.6 × 12 cm), had the plate index only on one side of the plate (red arrow).
The fake was bought from Amazon seller Oftalmico. This is just one of the many peddlers of fakes.
When you complain to them that their product is fake, this is their response. Paragraph breaks are mine — because of course they sent a wall of text.
Dear Sir,
I see your feedback and check the your return details.
Here is details for your ready references, you are comparing this book with 2007 which is more then 12 years old and according to time there are lots of changes made by Kanehara Trading till date.
Since 2016 they are not giving COA stamp/Sticker and also removed Notice Sheet because COA will be provide only on request and Notice details under the "copy right" message page.
Concerning Number on 4 sides is not required because Number Cards can be inserted in right position and direction but other graphical cards not inserted straight as it required according to Manual and Tests recommendation.
We receive lots of Feedback from Military Department that while they do test on New Recruitment they mix match each and replace the position of each card because Candidate use substitute of this book before coming for exams and give answer by rote memorization and these 4 sides printing of number will be easily to answer but incase series print only one side then it’s not easy to identify the card or graph.
Actual colour life for each card is not more than 3-4 years in really good condition and they faced during the time.
I hope this information is acceptable to you.
Nature Biotechnology cover
My cover design on the 7 April 2026 Nature Biotechnology issue shows the dendrogram that represents a cluster of uniquely expressed (or downregulated) genes in human naive stem cells induced from such cells. Within each dendrogram block, the genomic barcode sequence (sampled from Supplementary Table 1) is depicted with a Code 39 barcode. The highlighted barcode is one of those used for cell isolation.
Ishiguro S. et al. A multi-kingdom genetic barcoding system for precise clone isolation (2026) Nature Biotechnology 44:616–629.
Browse my gallery of cover designs.
Happy 2026 π Day—
Art for the 5%
Celebrate π Day (March 14th) and enjoy the art — but only if you're part of the 5%.
Go ahead, see what you can't see.
Ishihara's Tests for Colour Deficiency
Authentic and accurate images of Ishihara's test plates photographed (and lovingly color-corrected) from the 38-plate Ishihara's Tests for Colour Deficiency.
I also provide the position, size, and color of each circle on each test plate.
Symmetric alternatives to the ordinary least squares regression
What immortal hand or eye, could frame thy fearful symmetry? — William Blake, "The Tyger"
This month, we look at symmetric regression, which, unlike simple linear regression, it is reversible — remaining unaltered when the variables are swapped.
Simple linear regression can summarize the linear relationship between two variables `X` and `Y` — for example, when `Y` is considered the response (dependent) and `X` the predictor (independent) variable.
However, there are times when we are not interested (or able) to distinguish between dependent and independent variables — either because they have the same importance or the same role. This is where symmetric regression can help.
Luca Greco, George Luta, Martin Krzywinski & Naomi Altman (2025) Points of significance: Symmetric alternatives to the ordinary least squares regression. Nat. Methods 22:1610–1612.
Beyond Belief Campaign BRCA Art
Fuelled by philanthropy, findings into the workings of BRCA1 and BRCA2 genes have led to groundbreaking research and lifesaving innovations to care for families facing cancer.
This set of 100 one-of-a-kind prints explore the structure of these genes. Each artwork is unique — if you put them all together, you get the full sequence of the BRCA1 and BRCA2 proteins.
