Colour Vision Deficiency makes it difficult to see some colours or to tell some apart from others. The condition affects more than one in 20 males and a smaller but significant number of females in Australia. In the world, it affects one in eight males.
There are several tests you can find online (click here for iRo Lenses test) but the best one was developed 100 years ago, the Ishihara Test and is still the best test to see if you have the condition. Named after Dr Shinobu Ishihara, each of his tests consists of a set of coloured dotted plates, each of them showing either a number or a path. Since then this is the most widely used colour vision deficiency test and still used by most optometrists and ophthalmologists all around the world.
There exist four different types of plates for the test:
Vanishing design: Only people with good colour vision can see the sign. If you are colour blind you won’t see anything.
Transformation design: Colour blind people will see a different sign than people with no colour vision handicap.
Hidden digit design: Only colour blind people are able to spot the sign. If you have perfect colour vision, you won’t be able to see it.
Classification design: This is used to differentiate between red- and green-blind persons. The vanishing design is used on either side of the plate, one side for deutan defects and the other for protans.
See image below –
It is also well known, that even people with normal colour vision sometimes struggle with this test. But nevertheless, these plates are still in use in the absence of any better and still affordable colour vision test.
Even though you can find these as online tests they are not considered strong enough (computer colours vary, for example), so the best way to truly check is to visit one of our preferred Optometrists.
There’s a wide range of how colour blindness affects individuals, eye specialists now have a raft of further tests and equipment they can call on, including the RGB anomaloscope.
Having a colour vision deficit can make some things tricky, but it’s not serious. You can still drive, work, and live a normal life. You may need to find alternative ways to do some things, though. And our iRo Lenses can help. The iRo Lens testing kits are a cost-effective way to find out what you can see and if purchasing colour vision glasses is the best next step.