"Should I close my other eye or keep it open?" It is one of the first questions archers ask whoever is teaching them, and the answer depends on who gives it. Some coaches tell you to close the eye that is not aiming, because the second image of the sight disappears and the pin is easier to centre; others tell you the opposite, because with both eyes open you see the target better and tire less. In the end many archers settle for something in between and squint the eye without fully closing it.
On the precise question, whether one eye closed tightens the group, only two studies have had the same archers shoot both ways, and they reach opposite conclusions. In the registry the claim that aiming with one eye closed gives tighter groups is contested, and here I explain why: what the two studies measured, how much weight each one carries, and what is known about where archers look while they aim, which is the least familiar part of the answer. The topic borders on eye dominance, which I cover in a separate article: there the question is which eye does the aiming, here it is what to do with the other one.
What changes when you close one eye
When you aim, your eyes have to deal with two objects at very different distances: the sight, less than a metre away, and the target, tens of metres away. With both eyes open and your gaze on the target, the eye that is not aiming sees the sight from a different angle, and the sight doubles: this is physiological diplopia, which appears whenever you fix on a distant object with a near one in the field of view. Closing that eye removes the double image; the price is binocular vision, the means by which the brain compares the two images and works out depth.
You can build arguments either way about which of the two matters more, which is why measurements are needed. The Japanese group behind the second of the two experiments started from a hypothesis in favour of both eyes: by looking at the near sight and the distant target together, the archer might use the difference in distance as a depth cue and shoot better. As we will see, the hypothesis found no support in the scores.
The first comparison: three arrows at eighteen metres
The first study comes from South Africa and dates from 2010. It was a broader optometry project on the visual skills that matter in archery, and the comparison between one eye and two was one of its tests. The sample was twenty-eight archers aged 12 to 58, from beginners to experts, but the nine traditional archers, who do not use a sight, were left out of this test, so nineteen took it: eleven compound and eight recurve. Each shot three arrows at 18 metres at a white sheet of paper 90 by 50 millimetres: first with the non-aiming eye covered, then with both eyes open. The measure was the distance between the two outermost arrows of the group.
The authors run no statistical test between the two conditions. From the data they build reference bands, and in the average band the group runs from 52 to 90 millimetres with one eye closed against 59 to 124 with both eyes open; they conclude that aiming with one eye appears to be more beneficial. The limitations carry real weight, though. Three arrows per condition is very few for measuring a group, and the order was always the same, so the second set may have been affected by the first. The authors also write that one archer shot a 305 millimetre group with both eyes open and that without that figure the result might change: in this sample the advantage of the closed eye rests largely on one person.
The second comparison: thirty-six arrows at thirty metres
Thirteen years later, at Osaka University, a group of eye specialists and sport scientists repeated the test with a sounder design. Fourteen archers from the university club, with an average age of 20.7, shot 36 arrows per condition at 30 metres at an 80 centimetre face. Half started with both eyes open and half with the eye covered, so that fatigue weighed equally on the two conditions, and the non-dominant eye was covered completely with a patch. In all fourteen the eye looking through the sight was the right one, and it was also the dominant eye.
The patch made no measurable difference to the score. The total over 36 arrows was 257.6 points with both eyes open and 250.9 with the eye covered, with very wide differences between archers (the standard deviation is above 70 points in both conditions) and a difference between the means that the test cannot tell apart from chance (p = 0.22). The centre of the group stayed where it was too: it sat 4.67 centimetres from the centre of the target with both eyes and 5.33 with one (p = 0.83). In these archers, covering the eye neither raised the score nor brought the group closer to the centre. Group width, the measure used in the first study, was not calculated in Osaka.
The authors then counted how many arrows each archer put in each scoring ring, from zero to ten, and compared the two conditions ring by ring. The figure shows the averages for the rings that received at least one arrow.
No arrows landed in the three outermost rings, zero to two, so there are eight tested comparisons, and in seven of them the difference between the two conditions does not reach statistical significance. In the ten there are 6.64 arrows with both eyes and 6.50 with one; in the eight, 6.07 against 7.57, a difference well short of the threshold (p = 0.151). The only ring that crosses it is the nine, with 11.86 arrows with both eyes open against 9.36 with the eye covered (p = 0.047), and this is precisely the result the paper's abstract highlights. It needs careful reading: when you make eight comparisons, each with a 5% threshold, the chance that at least one crosses it by luck is far from small, and the authors applied no correction. With a p value just under the threshold and a total score that does not move, the nine cannot be read as an effect of keeping both eyes open, and in the registry I have not treated it as one.
What the two studies measure, and what they do not
| South Africa, 2010 | Osaka, 2023 | |
|---|---|---|
| Archers | 19 from a sample of 28 aged 12 to 58, compound and recurve | 14 from a university club, average age 20.7 |
| Arrows per condition | 3, at 18 m | 36, at 30 m |
| Order of conditions | always the same | crossed over between two groups |
| What is measured | group width | score, centre of the group, arrows per ring |
| Statistics | no tests | one test per measure, eight uncorrected comparisons for the rings |
| Result | tighter groups with one eye closed | no difference in score or in the centre of the group |
Side by side, the two papers do not measure the same thing: the first looks at the width of a three-arrow group, the second at the score and position of the group over thirty-six. In both, moreover, the two conditions are tried one after the other in the same session, and at least one of them is new to the archer: in Osaka the eye is covered on archers used to aiming with both eyes open, in South Africa each archer also shoots the way they do not normally aim. Neither compared archers who have shot for years with one eye closed against archers who have shot for years with both eyes open, and neither allowed time to adapt to the new condition. That is why the status is contested: the studies on archers point in opposite directions, the better of the two goes against the claim, but two studies are not enough to settle the question.
Where archers look when they aim with both eyes open
The Osaka study had a second part, which to my mind says more about what happens while aiming. Seven of the fourteen archers, chosen at random, repeated the test wearing a system that recorded their eye movements 240 times a second. With both eyes open five out of seven switched their gaze between the target and the sight right up to the release; with the eye covered, two did. In the archer the authors use as an example the difference is clear: with both eyes open the gaze goes back and forth between target and sight until the arrow leaves, while with the eye covered it looks first at the target, then at the sight, and stays there.
The authors read this back-and-forth as a way of using the distance between sight and target to judge depth. It is an interpretation, and the study does not link it to the score: it describes how the looking changes, not whether the result does. It does tell archers who shoot with both eyes open something concrete, though: fixing on a single point from start to finish is not what most of these archers do.
Another study, from Britain, shows in a different way how common the half-closed eye is. The researchers wanted to measure the quiet eye, the steady fixation on the target in the final part of the aim, in Olympic-level archers and in beginners. In pilot testing the camera-based eye trackers kept losing data because some archers closed or squinted one eye while aiming, so the researchers switched to electro-oculography, which records the electrical signal around the eye. It shows that the habit is common, not that it works. In the same study the Olympic-level archers held their gaze steady on the target for 1.96 seconds against 0.76 for the beginners, a link with accuracy that the registry rates as reported and that comes from a comparison between levels, not between arrows shot by the same archer.
The gaze during the draw
Then there is a measurement that runs against a deeply rooted idea. Archers are usually taught never to take their eyes off the centre, from the moment the bow comes up until after the release, because a gaze that moves would take the aim with it. In the registry, the only study that has tracked the eyes of expert archers during the draw comes from kyudo, traditional Japanese archery, and it is a two-page conference communication from 1994. Four university students with at least six years of practice and one beginner, wearing an eye tracker, repeated the shooting sequence four times, up to a five-second hold at full draw.
In the beginner the gaze stayed on the target from start to finish. In all four experts, by contrast, it was on the target before the draw and then dropped down and to the right, with the fixation points split into two clusters, and the shift began at the moment the body takes up the load of the bow. In each of them the path of the gaze repeated almost identically on every shot, even though it differed from one expert to the next. The authors suggest that aiming is handed over in part to peripheral vision, and they call this a conjecture themselves.
In the registry the claim that in expert kyudo archers the gaze does not stay fixed on the target during the draw is reported, and it cannot go further: five people, no figures, no statistics, a comparison with the beginner that rests on a single individual, and above all kyudo, which does not use a sight. The only data on the draw in recurve come from a 2019 Korean study of seven national team archers and seven university archers, who were watching a film of the shot recorded from the archer's point of view rather than shooting: in the set-up and the draw the two groups did not differ, and at the end both looked at the target and the sight. Watching a film is not shooting with a bow in your hand, so for recurve the question remains open.
Taken together with the Osaka results, these data sketch a less rigid kind of aiming than the one that is taught. The kyudo experts during the draw, and most of the Osaka university archers with both eyes open, do not keep their gaze pinned to one point but move it, and in kyudo they move it the same way every time. It remains an observation on a handful of archers, and no study has yet shown that these movements help anyone shoot better.
When the dominant eye is on the other side
The question about closing an eye often grows out of another one. Archers whose dominant eye is on the opposite side to their drawing hand are told to close one eye, or to switch to a bow for the other hand. The claim that cross-dominance between eye and hand worsens accuracy is contested too, and the sign of the data depends on who is shooting. Among 82 sport science students picking up a bow for the first time, with a beginner's recurve and no sight at 7 metres, those whose eye and hand were on the same side scored more than the cross-dominant ones. Among trained archers the advantage does not show: in 1986, across 81 American archers split into four score levels, cross-dominance did not separate the levels, and in questionnaires from 1,135 French archers the share of cross-dominant archers stayed between 15 and 19% from club to international level.
The authors of the French study think it is the sight that cancels out the beginners' disadvantage, but that is a hypothesis, because nobody has followed cross-dominant and same-side archers over time on the same training. For the practical side, which side to choose when you start and how to manage a dominant eye that is not on the side of the bow you use, see the article on the dominant eye.
What I take from this for the shooting line
The first point is that the data give no reason to change your habit. If you shoot with one eye closed and your group is stable, no study says that opening it will earn you more points; if you shoot with both eyes open, the better study found no advantage in covering one, at least in the first session. For now the choice is made on the range, by looking at your own groups, because the literature does not settle it.
The second concerns how to test it, if you want to. The two studies show clearly what to avoid: three arrows per condition, always in the same order, are not enough, because a single wide arrow weighs on the whole comparison, like the 305 millimetre group in the South African study. The Osaka design is closer to what is needed: a long set per condition, the order reversed (in Osaka between two groups of archers, on your own from one session to the next), and score measured together with the position of the group. Bear in mind too that the new condition is tried without any habit behind it, so a comparison made on the first day measures the novelty at least as much as the condition.
The third concerns the gaze. The measurements, few and small, say that kyudo experts do not keep their eyes still on one point throughout the draw, and that with both eyes open five university archers out of seven moved between the target and the sight right up to the release. Nobody has tested whether moving the gaze deliberately helps, so I would not turn it into a drill; but if, watching yourself on video or paying attention to how the shot feels, you notice that your gaze does not stay pinned to the centre, the available data give no sign that this is a problem.
What is missing
What is needed is a study of archers who habitually shoot with one eye closed and archers who habitually shoot with both eyes open, or a comparison made after a period of adaptation, with a sample larger than fourteen and the scoring rings analysed together rather than one by one. For the gaze, we need eye tracking on recurve and compound archers while they are actually shooting, with more people per level and the score of every arrow, to find out whether the gaze leaves the target outside kyudo too, and whether that movement simply accompanies the load of the bow or serves a purpose. Until then, on the question we started from, the two available studies leave the choice to the archer.