When I was a teenager I could hold my breath underwater for a little more than two minutes. That was after hyperventilating for a minute or so.
I could only make it to 2:10 if I (a) found something on the bottom to hold on to so I could stay still and not use any energy, and (b) close my eyes.
I found that I could stay down an extra ten or fifteen seconds with my eyes closed than with them open.
That makes sense. The brain uses more oxygen than any other organ in the body, and visual processing uses up a lot of that. By closing your eyes your brain was doing less work.