Thanks everyone for taking the time to respond. There was no possibility for confusion. There were two senior iaido instructors providing the feedback. Both commented that I blinked way too much (and one demonstrated by blinking his eyes quickly). This is for seitei iai. I am not conscious of blinking so much, but I obviously do as I was the only person to receive this specific criticism...and my sins in this regard were canvassed with great energy! Unfortunately neither instructor had any suggestions as to how to deal with the problem, except be conscious of the problem and concentrate on controlling it when doing kata. As the issue had been raised before by my primary instructor, I am always aware of the issue and try to consciously keep my eyes open. But this is clearly not working. I would say, it's not about not blinking at all during the kata performance, but considerably increasing the intervals between blinking (i.e. reducing the amount of blinking I do). While no-one else at my dojo seems cursed with this afflication, I thought some one else may have had to deal with it, which is why I though I would ask here. I am going to try closing my lids more, and relaxing my face muscles somewhat (another suggestion I've had) and see what feedback I get. I'll have to try to get someone to video me close-ish so I can see the problem. It's not something any one comments about in my normal life, so it does seem to be very specific to my performance of iai kata. Thanks again!