Some one once asked Jerry Barnhart, after a very fast string, what he saw when he shot? He answered, "I saw what I needed to see". A simple answer to a complex question, but what do you see? I suspect that many IPSC shooters don't know what they are seeing or don't see all that they should and that accounts for many unexplained misses. You could also be seeing more than you need for that particular shot and this is why you may be slower than you would like.
You must see something for every shot but what you see will vary with the difficulty and distance. Whether you shoot a dot sight or iron sights you must see the sight (dot) lift in recoil on the target, for the spot where it starts to lift is where the bullet will impact. It is possible to see your sight on the target and you pull the trigger, but because you do not actually see the sight (dot) lift from the spot where the bullet will hit, you have already started looking towards the next target and of course your hands make the gun follow your eyes and now you have pulled the barrel enough so that by the time the trigger falls and the bullet exits the barrel it is no longer on the target. You have a mystery miss. Not really a mystery at all so no one believes you when you say it's a double.
The dot advantage
Simply put a dot sight's beauty is that you can usually just focus on the target and bring the dot (which stays always focused) to the spot you want to hit. This is much less work than shifting focus back and forth as with iron sights and if you are older it may be near impossible to shoot iron sights fast as your eyes are just not up to the task. In order to eliminate this difficult task many matches are now set up with the targets close enough so that you will not have to bother with the drudgery of shifting focus, this is too bad as many people simply do not know what it takes to hit a far target at speed.
What you need to see at: 25 to 50 meters
Although you seldom use this in today's 5 meter matches it should be at least known to you in case you go to a real match somewhere it handy to know. For iron sights you must see the target sharply then change your focus so that you see the front sight in sharp focus with the rear sight also well defined (the target will be fuzzy) and concentrate on prepping the trigger ( by removing all the pre-travel on the trigger) and then smoothly pulling the trigger straight back with the tip of your finger. With a dot everything is the same but you can just focus on the target and hold the dot on it. See the dot or sight lift.
What you need to see at: 15 to 20 meter partials
You will need to see the target in sharp focus as before, in order to know where exactly to shoot at it, and then shift you focus to a sharply defined front sight with the outline of the rear sight in some focus,( the target will be slightly out of focus but defined enough to confirm you are aimed at the right spot) prep the trigger and press through. For a dot simply focus on the spot on the target you want to hit, bring the dot to it then prep the trigger and press through. See the dot or sight lift.
What you need to see at: 15 meter full or 10 meter partials, plates
Note that the A zone is about the same size as a plate so you will need to focus on the target then shift to a focus on the sight so both the target and sight are about the same sharpness ( the harder the shot the sharper you must see the front sight) with an outline of the rear sight, press the trigger through with the tip of your finger. For dots simply focus on the target, bring the dot to it, and press the trigger through with the tip of your finger. See the dot or sight lift off the target. When shooting steel targets with my dot sight racegun I look to see the bullet impact on the face of the steel plate to confirm my hit, this is not as fast as just seeing the dot lift but it guarantees a hit, and this is where a lot of mystery misses take place.
What you need to see at: full targets 6 to 10 meters
Now we are up to warp drive speed but don't crash you still need to see the spot you want to hit on the targets in good sharp focus and index on that, you must see at least the outline of your front sight ( or your dot) on the spot you are going to hit, press or slap the trigger straight back and see either your sight (dot) lift or the holes appear in the target or both ( yes you can easily see the dot on the target and the holes appearing) BUT you must see one of these or you may be missing ( or shooting a noshoot) A proper grip on the pistol and a good index is imperative as you will be shooting by feel with just a visual confirmation. You must dry fire with visual sight alignment to learn this, or practice with a watergun.
What you need to see at: full targets 3 to 6 meters (typical Ontario match)
Hyper-warp drive where finger speed determines the outcome, BUT you still need to see something. Look at the spot you want to hit (a sharper focus guarantees better hits but you must at least see the part of the target you want to hit), index to that spot, press or slap the trigger as fast as possible see the holes appear, index in the next target. If you are shooting a dot sight it is probably just in the way, so try to ignore it or look over it and just use your index to align with the targets. This is commonly referred to as point shooting. Again good grip and index is required, try pointing you gun (dryfire) with you eyes closed then open them, if the dot (sight) is on the spot you are pointing at you are good to go, if not find the dot ( sight), see how it feels in your hands, try again.
Next time, Target Acquisition, or how to look at something different with each eye.