At EK they will give you the Ishihara, which if you fail then leads to a CAD test. It is the only option. The Lantern test is outdated now. You cannot prepare for it, as it is a pass/fail test. Quite necessarily! You will have one chance to pass it and that is it. I fail the Ishihara each year at EK but I have a standing pass in the CAD test. Whatever test results you bring from your home country will be worthless. You WILL need to pass the CAD test here in Dubai.