What do you see?

Do you see a number '25' on the left circle and a number '29' on the right circle?

Do you know that people with colour blindness are not able to see them? Instead, all they see are 'spots'? Most of the circles to the right are nothing but spots to me." says a writer from http://www.toledo-bend.com/colorblind/Ishihara.asp who suffer from colour blindness. 

So, what do people suffering from colour blindness see?

So, what is colour blindness?

Colour blindness or colour vision deficiency is the inability or decreased ability to see colour, or perceive color differences, under normal lighting conditions.