With Ishihara project CTRLZAK Studio investigates the field of visual perception. The project consists of different creative expressions utilising various forms and materials. One of these expressions takes form in a collection of three carpets realised in collaboration with the French/Italian company cc-tapis. The series is a reference to the Ishihara colour test utilised to determine colour vision defects like daltonism. The Ishihara test consists of 38 plates containing groups of coloured dots of the same brightness on a white background. The subject examined has to recognize numbers or pathways that are usually invisible to daltonic people. In some cases though the table contents are conversely visible only to those with red/green colour deficiencies. The carpets designed by CTRLZAK Studio are inspired by those exact plates presenting patterns made by coloured dots which form an overall message decipherable only by colour-blind people. The three rugs have a different motif according to the message contained. With the Ishihara project CTRLZAK aims to bring attention not only on visual perception but aslo on the concept of perception as a whole. Only a small part of the viewers is able to entirely comprehend those messages. The project emphasizes different levels of reading, which can potentially vary for each human being. Thus the question arises: if the vision is subjective, is there an absolute basis for determining its nature?