I've seen military personnel using night vision goggles (NVGs). With their flight altitude, I don't think the enemy can notice them. I thought it may be due to eye strain, but other units use red lights during long jobs that need looking at a screen. Also, you should consider some fighter pilots have short missions and their eyes won't get tired from light.
I wonder why they don't use normal light. Normal light versus red light versus night vision. I never used night vision, but I don't think it's comfortable to use.