Re: However do military fighter pilots cope with 200 ft decision heights when flying single seat jets....
DH has an RVR associated with it: typically 200ft may be 550m or 1800ft RVR. Sure, transition from a defined cloudbase isn't much of a problem but most other conditions are, since the RVR values you're given aren't necessarily or even usually the "real" RVR that represents what you can actually see. The illustration below with different touchdown, midpoint and rollout RVRs (700/400/900m) shows why RVR readings don't tell you the actual RVR: definition "the distance over which a pilot of an aircraft on the centreline of the runway can see the runway surface markings delineating the runway or identifying its centre line." Anyone like to give an answer to the question at the bottom of the picture?
At DH you are required to to decide, based on what you can see, whether the aircraft trajectory - position and rate of change of position - is satisfactory to continue. The USAF Instrument Pilots School and other research organisations showed decades ago that (1) you need to assess whatever visual cues you can see for 3 seconds before you can make a judgement of where the aircraft is actually going, and (2) to tell whether its vertical path is correct you need to be able to see the touchdown zone.
So when it really matters, with minimum legal RVR, you have no chance of seeing touchdown zone lights at DH. Even if the atmosphere has a uniform 1800ft RVR, when your wheels are at 200ft, your eyes are going to be at least 4000 ft from the touchdown point so you can only see a few approach lights. 3 seconds earlier, when you really need to start the assessment you'll see even less.
So even if you are right on the glideslope at DH, if your vertical trajectory isn't also 100% right, you won't be able to detect it until you get a lot lower - by which time it may be too late to correct it. Illustrated below.
This is the major cause of poor visibility accidents recognised decades ago and was one of the driving factors behind the development of autoland systems.