In the retina at the back of the eye – the part of the eye that picks up light coming in – there are 2 types of cell, ‘rod cells’ and ‘cone cells’.

Rod Cells

The human eye contains about 130 million rods and the role of rod cells is to work and help us see in low light but they do not ‘see’ colours.

While working at night or in low light, our rod cells allow us to see things around us, but only in shades of grey and white. You may not have even noticed as they have a low spatial acuity.

Rod cells are stimulated by light over a wide range of intensities and are responsible for perceiving the size, shape, and brightness of visual images. As mentioned they don’t perceive colour and fine detail. These tasks are performed by the other major type of light-sensitive cell, the cone.

Rods are more numerous than cones in the periphery of the retina. If you want to see a dim star at night, try to look at it with your peripheral vision and use your ROD VISION to see the dim star.

Rod cells are named for the shape of their outer segment, which is a membrane-bound cylinder containing hundreds of tightly stacked membranous discs (see video)


Cone Cells

The human eye contains about 7 million cones.  Cone cells react to daylight and they help us to see the detail in objects. Cones require a lot more light and they are used to see colour and pick up colours and are responsible for high spatial acuity. The daylight vision (cone vision) adapts much more rapidly to changing light levels, adjusting to a change like coming indoors out of sunlight in a few seconds

There are 3 types of cone cells: ones that pick up red light, others green and others blue. By combining the messages from each set of cone cells, we get the wide range of colours that we can normally see.

Signals from the cones are sent to the brain which then translates these messages into the perception of colour. Cones, however, work only in bright light. That’s why you cannot see colour very well in dark places. So, the cones are used for colour vision and are better suited for detecting fine details.

If one or more of these types of cone cells is faulty, a person can be colour blind  as some people cannot tell some colours from others – these people are “colour blind”, or have a “colour vision deficiency” or as we call them “iRochromatic”

Someone who has a colour vision deficiency does not have a particular type of cone in the retina or one type of cone may be weak. How do you know if you have a deficiency?

That’s where iRo Lenses testing kit can help. The best way is to do a quick simple check using our unique in-home testing kit enables you to determine your level and depth of colour vision deficiency and then see exactly which iRo lens works for you with the in-home iRo Lenses testing kit.

This in home testing kit is more accurate than any online test and can assist in ascertaining what type of Red-Green colour blindness you have.

These kits will demonstrate how you will see new, more vibrant colours with the remarkable iRo Lenses.

To purchase your testing kit today click here/ or image above to find out more Then the next step once you have seen how amazing the iRo lenses really then find your nearest Optical outlet to purchase your exact colour correcting iRo lenses for you.