When JAR regulations were introduced I think it was very difficult for monocular pilots to meet medical standards. Things may have eased a little since. Some JAR states (the UK was one) have continued to allow pilots to fly within their areas of juridisdiction if they already held a licence, issuing a Class Two with licence limitations - my licence is only valid in the UK unless I obtain written permssion from other states. Other states may not have fully aligned to JAR- I belive France still licences private pilots in accordance with ICAO class two, which may allow monocular vision under certain circumstances with restrictions. In the UK we currently have a national licence which is regulated by driver standards and allows monocular flying.
Best thing to do is to contact the JAR Authority where you wish to fly (e.g. DGAC in France the CAA in the UK, LBA in Germany)
All this will change in the period 2012-2015 when EASA takes over Flight Crew Licensing in Europe. It may then be possible to meet the standard for a LAPL (Light Aeroplane Pilots Licence) with monocular vision subject ot a flight test, and if ICAO Class Two standards are adopted, for a Private Pilts Licence but the machine is still turining on this.
Alternatively find an N-reg aeroplane to fly- there are loads here in the UK though the rules for flying these may also change under EASA