I'm legally, (or illegally) blind in one eye. I can't even get a medical for an HGV. I'd be somewhat surprised if I could get a medical for an aircraft.
Are medical regulations different for an aircraft license in different countrys?
Not that it makes much difference, because I'm not very likely to try for an airplane ticket anytime soon.
Yes; at least for Private Pilot license or lower: Recreational license, or Light Sport Aircraft license. For both the LSA and Recreational licenses you're limited to flying only VFR and only in the daytime. you also are limited to flying no more than 50 miles from your home airport. For the LSA there are additional aircraft size and weight restrictions.
The Private Pilot (which looks like what this guy got) requires a 3rd class medical (the lowest) He likely got a "special issuance" after submitting additional documentation supporting his ability to fly safely and possibly with some additional flight restrictions.
Years ago I passed a 3rd class medical with both hypertension and diabetes. It didn't require a special issuance but it did require additional testing and documentation: An ECG for the hypertension as well as documentation that I had been on my meds (from the FAA approved list) for at least 6 months with no side effects and that they were controlling the condition. For the diabetes I had the same requirement regarding the meds as well as a requirement to test my glucose level every half hour while in flight.
There's currently a move within the FAA to change the requirements for Private Pilot to match the two lower licenses; that is, to not require a medical at all. In the more than 10 years that the "no medical" rule has been in affect for the lower license, there have been no accidents due to medical causes.
The two higher licenses (Commercial License, and Airline Transport Pilot) require a 2nd class, and 1st class medical respectively. A 3rd class medical is valid for 2 years, a 2nd class medical is valid for one year (two years if using for lower privileges) and a 1st class medical is valid for six months (or one year if using it for 2nd class privileges, or two 2 years if using it for 3rd class privileges)
