Amelia1730 is there any chance you could post a picture of the eye cups in the fully extended position so others can compare with their models? As others have said maybe they are not fully extended.
When I first tried out the Conquests at Minsmere (I volunteer there), I found I was getting blackouts until I got the eye cups right out. I found the eye cups unscrewed before I got them to twist up fully so had to screw them on tightly and then I could twist up fully. I still get blackouts with the 8x42 (original eyecups), but not 10x42 or 8x32.
When I first tried out the Conquests at Minsmere (I volunteer there), I found I was getting blackouts until I got the eye cups right out. I found the eye cups unscrewed before I got them to twist up fully so had to screw them on tightly and then I could twist up fully. I still get blackouts with the 8x42 (original eyecups), but not 10x42 or 8x32.