I dont know how old the guy is but here is some food for thought. I was diagnosed with a medical problem (which im not prepared to go into) a few years ago. It was a debilitating problem; one that i thought would end my dreams of serving as an officer in the RN. Nevertheless i perused my dream, and after a specialist medical was passed fit for service. Long and short of my ramblings is that, if this is your dream then chase it, and do not stop chasing until you can chase no further.
However success in the armed forces is dependant on the adherence to our values: courage, commitment, discipline, respect for others, integrity and loyalty. I would encourage anyone with a medical history to approach the application process with the courage and integrity that will be essential throughout their career.
I whish you all the best in your application
Mr T