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  • Sports & Vision

    Journey into the world of professional and Olympic athletes and learn how their vision affects the game and how sports can affect athletes’ eyes. 

    In baseball, can the batter really “keep their eye on the ball?”

    A baseball player swings a bat at a baseball. The player is a white man wearing a white uniform with red trim and a red helmet, and the back of his jersey reads: HILL 2. He is standing on a baseball diamond with green grass and red clay, and he swings the bat in front of a catcher wearing a blue uniform.There is a popular adage in learning to play baseball that says to “keep your eye on the ball” from when it leaves the pitcher’s hand to when it connects with the bat. But is that physically possible? No matter how good a player is, or how good their vision is, the answer is no.

    Professional baseball players have some of the best visual acuity in the sporting world. A study in 2019 found that over 81% of the players in the Los Angeles Dodgers’ and New York Mets’ systems had a visual acuity of 20/15 or better. The average visual acuity for a professional baseball player is 20/13, or approximately 30% better than what is considered normal vision at distance.

    An illustration of the human field of vision. It shows a bird's-eye view of a man with a gray shirt and brown hair, and there is a half-circle emanating from his face. The half-circle is divided into two yellow wedges on the sides that read: Side Vision, and one large green wedge in the center that reads: 3-D Vision.So why can’t they “keep their eye on the ball”? It has less to do with visual acuity and more to do with how fast eyes can move. Eyes track motion in two different ways: smooth pursuit and saccade. Smooth pursuit is when the eye follows an object as it moves, and saccade is when the eye jumps to a new position. When a Major League pitcher releases the ball, it is moving at 90 miles per hour on average. Smooth pursuit is fast enough to see the ball at this point. However, when the ball reaches about 20 feet away from the batter, the ball’s speed relative to the batter has increased and smooth pursuit can’t catch up. Instead, the batter makes quick calculations about the ball’s speed, height, and curve, and then uses saccade to quickly jump their eyes to where they anticipate the ball to be.

    Even famous Red Sox player Ted Williams (1918–2002), who was reputed to have “the fastest eyes in baseball,” admitted A black and white photograph of a white man in a baseball uniform. He is a young man with dark hair, and he wears a dark baseball cap with a stylized letter B on it. There is an autographed signature in the bottom right hand corner of the photo that reads: Ted Williams.he couldn’t actually see the ball when it hit his bat. According to Williams, “You usually lose sight a few feet away. Once or twice in my whole life, I’d say I saw the ball hit the bat, but that’s all.” Even that claim is very unlikely. Luckily, based off of William’s excellent batting record, not being able to “keep his eye on the ball” really didn’t matter that much.

    Why does it hurt when sweat gets in your eyes?

    An illustrated diagram of a human eye and the system that makes tears. There is a drawing of an eyeball with a red, textured gland in the upper left hand corner labelled: Lacrimal gland makes tears. The bottom corner of the eye is connected to a large pink tube labled: Punctum, Canaliculus, Lacrimal Sac. There are two blue arrows flowing across the front of the eye, and one arrow flows down the lacrimal sac and is labeled: Nasal Cavity, Nasolacrimal Duct. The cornea needs tears to keep it lubricated and protected. But why does another salty liquid, sweat, irritate the eyes while exercising or playing a sport? While tears and sweat are very similar in makeup, they take very different journeys before entering the eyes.   

    Tears are a result of the lacrimal system. There is a lacrimal gland above the upper outer corner of each eye that produces tears, which then flow into the eye and are spread across the cornea by blinking, and then drained away through the tear ducts in the inner corner of each eye. When the lacrimal gland is producing more A close-up image of a woman's face covered in drops of sweat. The woman is white and is wearing pink lipstick, and the photo is cropped to only the right side of her nose, lips, and cheek. tears than the tear ducts can drain quickly, the excess fall down the face. This can happen because the eye is trying to clear an irritant, because of emotional triggers, or because of an obstruction of the tear duct system. Tears are mostly made of water, but also contain lipid oils, mucus and electrolytes. When tears are caused by emotions, they also contain hormones.

    Sweat, on the other hand, comes from pores all over the body, including near the eyes, and is pretty similar in composition to tears. Sweat is also mostly water, but contains trace amounts of minerals like salt, lactic acid and urea. Since sweat is produced all over the body, it must flow over the face or through the scalp and hair before getting into the eyes. This gives it a chance to pick up germs, skin, dust, hair and skin care products, all of which will cause the eyes to sting. Also, when the eyes sting from sweat, people are more likely to rub their eyes, irritating them further and introducing germs from the hands, which can cause even more irritation. 

    How dangerous is basketball for athletes’ eyes? 

    A medical scan showing the back of a human eye. The scan is circular and colored orange. There are small dark orange lines flowing through the scan, and there are raised, wave-like lifts in tissue. Basketball is the leading cause of sports-related eye injuries in the United States. Players often receive facial injuries from the ball or other players’ fingers or elbows. These injuries can result in scratched corneas, blood-shot eyes (subconjunctival hemorrhages), or pools of blood collecting in the orbital socket or in the eyeball itself (orbital hematoma and hyphemia, respectively).

    One of the most dangerous injuries players face in basketball is a rhegmatogenous retinal detachment. This is the most common form of retinal detachment, where small tears in the retina allow the gel-like vitreous fluid to seep behind it, pushing the retina away from the back of the eye and causing it A black and white photograph of a young Black man with a purple border. He has short dark hair, and is shirtless. He is looking past the camera to the right.to detach. When a basketball player receives a blow to the head, it can create these small tears. While they can be fixed by surgery, they can also cause severe visual loss. Luckily, the risk of these injuries can be significantly lowered by using protective eyewear.

    Retinal detachments are also common among boxers and wrestlers. Professional boxer and Olympic gold medalist “Sugar” Ray Leonard won four boxing victories after a surgery to fix a detached retina in 1982.

    In archery, riflery, or biathlon, is it better to shoot with one eye open or two?

    A photograph of a young Korean woman firing a compound bow and arrow. She is wearing a white collared shirt and a white bucket hat with plaid lining. She also wears large, black framed glasses and keeps both of her eyes open. She is drawing back the string of the bow, and holding it against her lips. Your brain determines depth and distance by knitting together two separate views from each of your eyes into one three-dimensional image. However, you have one eye that is dominant. In people with normal eye alignment and visual acuity, your dominant eye is the one that the brain “prefers” for most of its information. In people with strabismus (misaligned eyes), the dominant eye is usually the eye that is aligned correctly or the one that has the clearest vision.

    So, when athletes fire a bow and arrow or rifle at the Olympics, do they use their dominant eye or both eyes, and which is better? Most professional archers or shooters A photograph of a young, white man firing a sport rifle in a competition. He is wearing red, white, and blue skiing gear, including a sweatband a round his head. His shirt bears the five circle logo of the Olympic Games and it reads: Salt Lake 2008 48. He stands in profile and aims a rifle with a brown, wooden body towards red and blue flags along the left side of the photo. shoot with both eyes open, but this is a choice rather than a necessity. Whether to shoot with one or both eyes comes down to preference, and there are positives and negatives to both.

    An Olympic bow or rifle has a sight — a set of pins on the bow or barrel used to help aim at a target in the distance. When an athlete is aiming during a competition, they are focusing their vision first on this sight and then the target second. When an archer shoots with one eye open, it can feel easier to focus the dominant eye down the bow sight, but opening and closing one eye over and over in a competition setting can cause facial stress. When an archer has both eyes open, they can use their three-dimensional vision to locate the target but the bow sight can pull focus, causing double or blurry vision.

    So, it really comes down to the athlete’s preference. If they have two eyes that are equally aligned with similar acuity, they should be able to shoot equally well with one eye open or two. It just depends on what they are most comfortable with.

    Can you get a sunburn on your eyes?

    A close-up photograph of a human eye with a very red and veiny white portion of the eye. The person is white, and their iris is colored brown.Yes! This is a concern for Olympic sailors, skiers, snowboarders and many other professional athletes. Photokeratitis, the medical term for eye sunburn, is eye damage caused by the UV spectrum of light. Photokeratitis can affect both the outer layer of the cornea and the lining of the white of the eye (the conjunctiva). It can be very painful and may result in redness, pain, and blurry vision, among other symptoms.


    A photograph of two athletes sailing a catamaran sailboat. The sailors are both white and wearing blue uniforms with the letters ARG on them. One athlete wears sunglasses and a baseball cap, and the other wears sunglasses and a helmet. The boat has a white body with blue portions that read: Tokyo 2020 ARG. The athletes are holding ropes and and leaning out off of the boat over the blue water.

    Water, ice and snow are all reflective surfaces, so Olympic sailors, skiers and snowboarders are exposing their eyes to the sun’s UV rays both coming down from the sky and reflecting up from the surface of the water or snow. Snow-blindness, a specific type of photokeratitis, can be very severe — not only because of snow’s reflective properties, but because the thinner air at higher altitudes and higher latitudes provides less protection against UV rays. Sunglasses and snow goggles that are coated with UV protection can block out most of this harmful radiation and prevent burns.

    Does high altitude affect mountain climbers’ eyes?

    A photograph of four mountaineers walking across a white, snow-covered ridge. The ridge appears very high, and there are both tall mountains in the background. The mountaineers all wear backpacks and helmets and carry ski poles. Yes! Climbing any mountains at high elevations can cause injuries due to UV rays and cold temperatures, but certain very high altitudes can cause high altitude retinopathy (HAR). HAR usually occurs in altitudes above 12,000 feet (about 3,460 meters) or higher. So HAR is mainly a concern for very advanced or competitive mountaineers. In the United States, the Rocky Mountains and the Sierra Nevadas do have peaks this high, but there are no mountains over 12,000 feet east of the Mississippi River.

    Six medical scans of the back of a human eye. The scans are all circular, and shades of red, orange, and pink. All of the scans have darker lines flowing through them indicating veins, and the veins grow progressively more swollen as the images go on.
    HAR can cause over-dilated retinal veins and arteries, optic disc swelling and hemorrhages in the retina and vitreous. Luckily, HAR is almost always asymptomatic, and it recedes after a return to a lower elevation. The severity of HAR can be mitigated by slower ascents, acclimatization to higher altitudes, and the use of supplemental oxygen when climbing.



    Can you play professional sports with an ocular prosthetic?

    Nine white acrylic semi-circles sit in individual compartments of a white box lined in black velvet. Each semi-circle has a design mimicking a human iris and pupil.It’s possible! Former professional basketball player Isaiah Austin wears an ocular prosthetic in his right eye. When he was 14 years old, Austin completely detached his retina after several sports injuries. Around the age of 17, he lost sight in that eye completely and opted to have his eye removed and replaced with an ocular prosthetic. Afterwards, Austin was able to learn how to play with his remaining sight. Although he only has mono vision, he developed a play style where he moved often and was able to check shots from multiple angles with his left eye.

    Even with his prosthetic, Austin was the #3 overall college recruit in 2012. He played two years at Baylor University in Waco, Texas, and declared for the NBA draft in 2014. He went on to play professional basketball overseas until his retirement in 2021.

    A young, tall Black man holds a microphone. He has short, dark, curly hair, and light brown skin. His eyes are brown, and one iris appears larger than the other. He wears a gray hooded sweatshirt.Since Austin stands at 7’1” and is taller than most people, his ocularist (a professional who makes ocular prosthetics) took special care to calibrate his prosthetic so it looks the most natural at a downward glance. Having only one eye doesn’t mean that people can’t live a normal life, but playing sports professionally with only one eye takes a lot of practice and skill.