I voted for both eyes open.....I bought a new Diamond Triumph in September 2006. I never realized how fast the new bows were until I tried following my arrow. I had an old XI and never had this problem b/c it was soooo slow. Also, I changed to bi-focals the same monthand thought itwas the glasses and myfast new bow were the reason I couldn't see the arrow anymore. Then, I was reading here about keeping both eyes open while shooting and I discoved I was closing my left eye while practicing. Once I opened my left eye, I could see my arrow andrealized my problem. I am left eye dominant and have struggled with aiming my bow and following a deer. SO...this past year I practice just about every day from August to October totrain my left eye to stay open. What a difference...I could follow my arrow once again and I became a more accurate shot. I finalyy became more confident with my bow! Guess what...I shot a buck this year and under pressure, I think I closed my eye, b/c I never saw where I hit that deer. Old habits die hard.....but....maybe another year of practicing and I'll get it right next year.