Military
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 27
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
General Declared Emergency
Human Factors; Procedure
Aircraft X called wanting a frequency to file a VFR OTP flight plan.  I identified the aircraft and asked if he could maintain his own terrain and obstruction avoidance through 025.  He stated that he could; so I issued the clearance.  He reported on top at 014 which was below a layer that had been giving VFR pilots trouble.  I was concerned about the aircraft being on top so far below the MIA that I restated the clearance and the aircraft started to climb. I was busy so I put in a VFR on top flight plan and then did other tasks.  Soon after; Aircraft X declared an emergency and stated that he was turning to land at ZZZ.  I obtained the emergency info and issued distance and direction to the airport.  He got the airport in sight and I gave him a phone number to call so we could know he arrived safely. Later; I realized that I treated him like a VFR aircraft.  I never issued him an altitude to maintain nor did I clear him for a visual approach.  These are things I would do with any other aircraft.  I assume I made this mistake because I never updated the data block to show VFR/OTP and the VFR in the data block just led me down the wrong path.  The aircraft landed safely.I could tell that I was getting behind so I should have asked for help.  Also; I would update the data block immediately or if I had help I would use the template.
Controller describes a situation where the aircraft is VFR on top and declares an emergency.  The aircraft is never given an altitude to maintain or a clearance for a visual approach to the airport.