As coaches, maybe the first thing we notice about an athlete
is their height in relation to their age. We might notice that bang from a
fluid canon of an arm sending some poor Molten Pro Touch to its wooden grave.
We might even go one step beyond and look at the length of a player’s arms, the
size of their hands or the length of their calves which may have direct
correlation on their subsequent performance.
Maybe what we should be looking at is their eyes!
Athletic performance and eye sight go hand in hand with
sports that require quick movements and reaction time. Between 1993 and 1995, a
group of ophthalmologists tested the vision of 387 players in the Los Angeles
Dodgers organization. A normal human’s eyesight is considered perfect when it’s
20/20 but the Dodger’s players AVERAGED 20/13 and only a small number of
players, usually pitchers, were worse than 20/20. In fact, 2% of those tested
leaned against the theoretical threshold for the human eye, (thought to be 20/8
vision) testing in at 20/9! A similar study of U.S. Olympic athletes found
elite softball players to average a visual acuity of 20/11!
Darlene Kluka is a preeminent expert of visual acuity in
sports at the Barry University School of Human Performance and Leisure Sciences
in Miami Shores, Florida. “Vision just may be the most variable and selective
of all the senses.” She says. “Attempting to observe fast movements that occur
in sport places great demands on human vision.”
She helps break down the process we all take for granted.
“The eyes send information to the brain, where it is integrated and interpreted
as a three dimensional (3D) phenomenon. The information from both eyes into a
3D image is called fusion. Fusion is needed to accurately locate the ball when
it moves in time and space.”
Kluka points out that without a conscious effort to attend
to something, the eyes will continuously move throughout the field of vision. “When
something gets our visual attention, we may focus both eyes on the object. This
pause is called a fixation.” She says.
Now why is it important that we know about fixations you
might ask? “Fixations are important because focusing ability is limited to only
3 degrees of visual angle.” Kluka comments. She points out if you hold your
thumb straight out in front of you and look at your thumb nail—that is
approximately 3 degrees of visual angle! Kluka adds, “It is assumed that when
your eyes fixate on something, information is being recorded by your brain to
assist in visual perception or the decision making prior to motor program
initiation. The rest of what you see is peripheral.”
As you read this blog, (all three of you), your eyes must
move so that the 3 degrees of visual angle are used to pick up the words while
the peripheral vision provides a view that there are additional words to either
side of your focus.
Two athletes that have a lot in common are a hockey goalie
and a libero. They are subject to super human reflexes and reactions and their
play can dictate their team’s success or failure more often than not so it
should be asked, what are these athletes fixating on when playing?
Researchers
at the University of Calgary's Faculty of Kinesiology have found that the
difference between elite goaltenders is what their fixation is on before they
make a save; the puck. The best
goaltenders rest their gaze directly on the puck and the shooter’s stick almost
a full second before the shot is released making the save 75% of the time.
Graduate student Derek Panchuk says, “Looking at the puck seems fairly obvious
until you look at the eye movements of novice goaltenders, who scatter their
gaze all over the place and have a much lower save percentage than the elite
goalies.” The study also showed the distance of the shot doesn't seem to
matter, as long as the goalie concentrated their gaze on the puck and stick in
the critical second before it's released.
Two-time United
States Olympic libero Nicole Davis shares an interest in these studies. The
Women’s USA National team coach Karch Kiraly and Davis were working on this in practice
just this week. “I have been
working on seeing the line of the serve earlier.” Davis says, who has 20/16
vision. They conducted an experiment where Nicole alternated between focusing
on the ball for 8 serves, and then focusing on the server's arm for 8
serves, for several rounds each.
“With pretty
conclusive numbers, when my focus is more on the BALL in serve receive, from
toss, through the line to contact, my results were much more consistent in
terms of how early I saw the path, how early I got my angle out and also my
ability to make last minute adjustments, as well as quality of the pass.” Davis
says. “Obviously, or maybe not, it's a little counter-intuitive to stare
at the ball, because the server is the one acting on the ball and giving you
the cues as to where the ball might go. All of that comes into view, in a
wider focus (peripheral), as the server is contacting even though the focus is
mainly on getting a good look and following the ball.”
The National team
also experimented with eye goggles that had a tracking device on them to see
what players were watching while playing defense. (You can see a sample of
these on this video with soccer star Renaldo ) “One thing that we noticed in common for those of us getting a good
‘read’ on the situation, is that we get our eyes on the next actor of the ball
quite early.” Davis observed, adding conversely from serve receive, “Not a lot
of time on defense is spent staring at the ball.”
Unlike serve receive,
the trained eye moves past the fixation point and to what will come next. “Once
we see the quality of the pass, before it reaches its peak, the eyes
immediately shift to the setter's contact point and relation to her body, so
often her shoulders and hands.” Davis points out. “Once the setter releases the ball, the
eyes shift immediately to the hitter, and more specifically the hitter's
shoulder and elbow.”
There are lots of
clues that setters and hitters give defenders that tell them where they are
setting or hitting, but Nicole says the shoulders often are the easiest tell.
“Hitters tend to have a lot of tension in their torso when they are
hitting hard, or will kick up their legs and not pull the elbow back as far
when hitting off speed or roll shots. Setters will take the ball at
different points, some will pivot and some will square to the set while others
might try to disguise it longer. There is a lot of information to
process on defense in a split second, so the earlier you can get on the actor
of the ball and pick up the tells, the earlier read you can make.”
A different set of visual skills seems necessary for serve receive and
defense. “My theory as to why the sequence is a little different for serve
receive is that the ball has longer to travel and can often change direction,
and it's important to follow it from start to finish.” Davis surmises.
Kluka agrees with Davis. “Focusing visual attention on important cues
while visually searching can lead to good decisions in competition. This has
been referred to as effective anticipation.” She adds, “Skilled volleyball
athletes may not be aware of the important visual cues they are attending to.”
Kluka sums up the role that Coaches can play in the enhancement of a
player’s vision. “As coaches develop and use drills, drill objectives are
important. Each drill must have multiple objectives that have measureable
outcomes, one of which includes visual perception and decision making. By
including this objective to each drill, coaches are more likely to find
multiple outcomes that are in a more game-like environment.”
