If you are colour deficient you know that the eye has four types of light receptors—rods, that are good for night vision, peripheral vision, and motion changes and three types of colour-sensitive cones which are responsible for central vision and colour.
A simplified theory of colour vision states that there are three primary colours, (red, yellow and blue) that correspond to the three types of cones and that various combinations of the primary colours produce all the hues. Just like when you mix colours on a paint pallet.
When you think about how we see colour in more detail from just the three primary colours it is impressive.
Then there is another factor that comes into play – our brains, which also helps discern colour no matter what the circumstances are. For example, the eye-brain colour-sensing system can, by comparing various objects in its view, perceive the true colour of an object under varying lighting conditions — an ability that is called colour constancy.
We can sense that a white tablecloth, for example, is white whether it is illuminated by sunlight, fluorescent light, or candlelight. We still know it is white.
One theory that takes various factors into account was advanced by Edwin Land (1909–1991), the creative founder of the Polaroid Corporation. Land proposed, based partly on his many elegant experiments, that the three types of cones in your eyes are organised into systems called retinexes. Each retinex forms an image that is compared with the others, and the eye-brain system can compare a candle-illuminated white table cloth with its generally reddish surroundings and determine that it is actually white. This retinex theory of colour vision is an example of modified theories of colour vision that attempt to account for its subtleties. One striking experiment performed by Land demonstrates that some type of image comparison may produce colour vision.
Two pictures are taken of a scene on black-and-white film, one using a red filter, the other a blue filter. Resulting black-and-white slides are then projected and superimposed on a screen, producing a black-and-white image, as expected. Then a red filter is placed in front of the slide taken with a red filter, and the images are again superimposed on a screen. You would expect an image in various shades of pink, but instead, the image appears to humans in full colour with all the hues of the original scene. This implies that colour vision can be induced by a comparison of the black-and-white and red images. Colour vision is not completely understood or explained, and the retinex theory is not totally accepted. It is apparent that colour vision is much subtler than what a first look might imply.*
The exact physical causes of colour blindness are still being researched but it is believed that colour blindness is usually caused by faulty cones but sometimes by a fault in the pathway from the cone to the brain.
People with normal colour vision have all three types of cone/pathway working correctly but colour blindness occurs when one or more of the cone types are faulty. For example, if the red cone is faulty you won’t be able to see colours containing red clearly. Most people with colour blindness can’t distinguish certain shades of red and green.
Try our iRo Lenses today!
The iRo lens ‘home testing’ kit will enable you to determine which lens is best suited for you so you can enjoy new more vibrant colours for the very first time. This process is straightforward and comes with a step by step guide to assist you in selecting the most appropriate iRo lens for you.
These filters in the home testing kit show you exactly how you will see your new more vibrant colours with your iRo lenses. You can take them outside, look around and see your amazing new world of colours and see the world in all its beauty. So even if you don’t decide to purchase the iRo lenses these filters will at least show you how vibrant all the colours actually appear.
The next step is to purchase a testing kit click here, and if you enter in this code on check out you can receive the kit for half price – COLOUR
We will mail them out to you straight away and there is even an instruction video on our YouTube Channel on how to use the kit Click here to view
Once you have seen how amazing the iRo lenses will be for you then you may wish to purchase our iRo frames and lenses and this can be done over the phone or online.