This may be an issue for you.
At the EK medical (last day if you pass everything), you do a color test at the EK in-house doctors, then they send you to an external eye clinic and its done in more depth again. It is probably worth emailing EK and getting in contact with a UAE doctor, as I can tell you the EK medical is very very extensive. I can give you the contact information for the external eye clinic if you like. Will probably be easier to ask them directly then go through EK. The entire medical took me about 8 hours to complete....