Sports Vision (Evaluation and Improvement of Dynamic Visual Acuity and Depth Perception) (Sports Vision and Visual Performance)

Key points at a glance

Key Points at a Glance

• Sports vision is a general term for visual functions related to athletic and sports performance, consisting of multifaceted elements that cannot be evaluated by static visual acuity alone.
• The six main components are dynamic visual acuity (DVA), depth perception, eye movements, peripheral vision, visual reaction time, and contrast sensitivity.
• It has been reported that professional baseball players have significantly better dynamic visual acuity than the general population³⁾.
• Depth perception (three-rod test) is used in aptitude tests for large vehicle and special licenses, with a passing criterion of error within 2 cm.
• Vision training can improve some visual function indicators, but the evidence for a direct effect on athletic performance is moderate⁹⁾.
• To prevent eye injuries in ball sports, wearing polycarbonate protective eyewear (sports goggles) is recommended¹¹⁾.
• Next-generation vision training using VR/AR is in the research stage, and practical application is expected¹⁵⁾.

1. What is Sports Vision?

Sports vision is a general term for visual functions related to athletic and sports performance¹⁾. Unlike static visual acuity (the ability to identify stationary targets) measured in routine eye exams, it encompasses dynamic and complex visual processing abilities.

Even if static visual acuity is 1.2, if dynamic visual acuity to track a moving ball or depth perception to accurately perceive distance is insufficient, sports performance will be limited. When athletes feel that they “should be able to see but react slowly” or “cannot judge distance,” there may be problems with visual functions other than static visual acuity.

The main components of sports vision are as follows:

• Dynamic Visual Acuity (DVA): The ability to identify moving targets
• Depth Perception (Stereopsis): The ability to accurately perceive depth and distance
• Eye Movements: Saccades (rapid eye movements) and smooth pursuit (tracking movements)
• Peripheral vision: The ability to use visual information outside the central visual field
• Visual reaction time: The time from visual stimulus to motor response
• Contrast sensitivity: The ability to discriminate under low contrast and low illumination

It has been reported that the dynamic visual acuity of professional athletes is significantly superior to that of the general population³⁾. In a study of professional baseball players, ocular dominance did not significantly affect batting average or earned run average²⁾.

Q What is the difference between dynamic visual acuity and static visual acuity?

A

Static visual acuity (static vision) indicates how finely one can identify a stationary target (such as a Landolt ring). In contrast, dynamic visual acuity (DVA) is a measure of the smallest size of a moving target that can be identified. The ability to see fast-moving objects, such as a baseball or tennis serve, depends on neural mechanisms different from those for static visual acuity, and even if static visual acuity is normal, dynamic visual acuity may be reduced.

2. Components of Sports Vision

Dynamic Visual Acuity (DVA)

Definition: The ability to identify a moving target

Identify the direction of the gap in a Landolt ring for targets moving horizontally or vertically¹⁾. It is one of the most important indicators in ball sports.

Depth Perception (Stereopsis)

Definition: Accuracy of depth and distance perception

It depends on binocular stereopsis, calculating distance from the disparity between the left and right eyes⁴⁾. In the aptitude test for large and special vehicle licenses, an error of 2 cm or less in the three-rod test is the passing standard.

Eye Movement

Definition: The ability to direct and follow a target with the eyes

It consists of saccades (impulsive eye movements: instantaneous gaze shifts between targets) and smooth pursuit (tracking movements: smoothly following a moving object)¹⁾.

Peripheral vision and visual reaction time

Peripheral vision: The ability to use visual information outside the central vision. Important for situational judgment in ball sports⁵⁾.

Visual reaction time: The time from visual stimulus to motor response is 100–250 ms. Soccer players have shorter times than non-athletes⁶⁾.

Contrast sensitivity and convergence/divergence

Contrast sensitivity reflects the ability to identify targets under low-contrast conditions or low illumination⁷⁾. It is especially important for sports in changing visual environments such as night, rain, or early morning. Reduced contrast sensitivity affects functional vision even when static visual acuity is normal.

Convergence/divergence ability is responsible for the accuracy of binocular vision at close distances. It is involved in distance judgment in sports requiring close combat, such as martial arts and table tennis.

Components and related major sports

Visual function component	Particularly important sports	Evaluation index guideline
Dynamic visual acuity (DVA)	Baseball, tennis, badminton, table tennis	DVA test value (approximately 0.1–0.8)
Depth perception	Baseball, basketball, golf, motor sports	Three-rod test error (license standard: within 2 cm)
Eye tracking movement	Tennis, soccer, racket sports in general	Tracking accuracy, deviation frequency
Peripheral vision	Soccer, basketball, ice hockey	Visual field angle (degrees)
Visual reaction time	Martial arts, sprinting, squash	Reaction latency (ms)
Contrast sensitivity	Golf, shooting, archery, night sports	CSV-1000 score

Q What sports are affected by poor depth perception?

A

Depth perception (stereopsis) depends on binocular vision, so people with monocular visual impairment or weak stereopsis have reduced accuracy in distance judgment. In baseball batting, it affects the sense of distance between the ball and bat; in tennis receiving, it affects the depth of the ball’s trajectory; in basketball passing, it affects distance judgment with opponents. Reduced depth perception also affects driving, and for large vehicle and second-class licenses, the three-rod depth perception test (error within 2 cm) is a statutory fitness standard.

3. Sports events and required visual function profiles

The priority of required visual functions differs depending on the type of sport. It is efficient to conduct vision assessment and training based on an understanding of the characteristics of each sport.

Sport	Highest priority visual function	Second most important visual function	Special notes
Baseball	Dynamic visual acuity (DVA)	Depth perception / Eye tracking	Batters need to respond to ball speeds of 150 km/h or more
Tennis	Dynamic visual acuity / Eye tracking	Visual reaction time	Responding to serves over 250 km/h
Soccer	Peripheral vision	Eye movement / Visual reaction time	Understanding the overall field situation is important5)
Basketball	Peripheral vision, depth perception	Eye movement	Both are needed for high-speed pass judgment
Golf	Depth perception, contrast sensitivity	Static visual acuity	Judging distance and subtle elevation changes of terrain
Shooting, Archery	Static visual acuity, ocular stability	Contrast sensitivity	Judging fine position of target
Martial arts	Visual reaction time, peripheral vision	Dynamic visual acuity	Immediate response to opponent’s movements
Auto racing	Dynamic visual acuity, depth perception	Peripheral vision	Understanding front, back, left, and right situations at high speed

Current status of sports-related eye injuries

Hyphema due to blunt eye trauma (traumatic hyphema occupying about half of the anterior chamber)

Ahuja R. Hyphema - occupying half of anterior chamber of eye. Wikimedia Commons. 2006. Figure 1. Source ID: File:Hyphema_-_occupying_half_of_anterior_chamber_of_eye.jpg. License: CC BY-SA 2.5.

Clinical photograph of traumatic hyphema (traumatic hyphema) with red blood cells filling about half of the anterior chamber, showing blood pooling with a fluid level in the anterior chamber between the posterior corneal surface and the iris. This corresponds to sports-related eye injury (blunt eye trauma) discussed in section “3. Sports events and required visual function profiles”.

In soccer, eye injuries are an important public health ophthalmology issue. Soccer balls deform upon impact, enter the orbit, and deliver blunt force to the eyeball. Polycarbonate protective eyewear compliant with ASTM F803 is said to prevent ball contact, and its use is strongly recommended ¹¹⁾. It is important to select contact lenses suitable for use during sports and to ensure proper fit.

4. Methods for evaluating sports vision

Each element of sports vision is evaluated using specialized testing equipment and methods. These can be performed at facilities specializing in sports ophthalmology, or at university ophthalmology and sports science laboratories.

• Dynamic visual acuity (DVA) evaluation: Using a DVA testing device, the minimum visual angle that can be identified is measured by varying the speed of a rotating or linearly moving Landolt ring ¹⁾. A speed of 0.3 to 0.8 is considered a general adult standard.
• Depth perception evaluation: Using a three-rod test apparatus. The center rod moves forward and backward, and the subject judges when the three rods are aligned in a straight line. This is also used in aptitude tests for large vehicle and special vehicle licenses, with a passing criterion of error within 2 cm.
• Eye movement evaluation: Saccades and smooth pursuit are measured using an eye movement recording device (eye tracker) ⁸⁾. Tracking accuracy, deviation frequency, and latency are quantified.
• Peripheral vision evaluation: In addition to measurement with an automated perimeter, for sports applications, a combined task involving target detection and response within the visual field is used ⁵⁾.
• Visual reaction time evaluation: Computer-based light stimulus reaction time measurement. Simple reaction (press a button when a light appears) and choice reaction (discriminate left/right and press) are measured ⁶⁾.
• Contrast sensitivity assessment: Use standardized charts such as the Pelli-Robson chart or CSV-1000 ⁷⁾.
• Convergence and divergence assessment: Measure the amount and speed of binocular convergence and divergence using the near prism bar method.
• Standard eye examination: Perform static visual acuity, intraocular pressure, fundus, and refraction tests together to rule out organic diseases (glaucoma, cataracts, retinal diseases).

Q Where can I get a sports vision evaluation?

A

Facilities that can provide specialized sports vision evaluations include ophthalmology clinics specializing in sports ophthalmology and sports medicine, ophthalmology departments at university hospitals (especially those collaborating with sports medicine divisions), and physical education universities or comprehensive universities with sports science research laboratories. Since specialized equipment such as DVA testing devices and eye movement recording devices are required, the available evaluation items vary by facility. It is advisable to confirm the target test items before visiting.

5. Vision Training and Improvement of Visual Function

Vision training is a general term for training that purposefully exercises specific elements of visual function. It ranges from scientifically validated methods to commercially popular ones, so it is important to use them based on the quality of evidence.

Main Training Methods

• Dynamic visual acuity training: Practice tracking moving objects. A gradual increase method that progressively increases speed is used ⁹⁾. A study targeting youth field hockey players reported that a sports vision training program improved multiple visual function indicators ⁹⁾.
• Eye movement training (saccade training): Practice moving the gaze quickly and accurately between two specific points. It enhances the efficiency of neural circuits including the frontal eye field and superior colliculus ⁸⁾.
• Peripheral awareness training: Practice detecting targets in the peripheral visual field while maintaining central fixation. It aims to improve situational awareness in ball sports ⁵⁾.
• Visual reaction time training: Light stimulus reaction training where you move a button or your body as quickly as possible in response to a light stimulus ⁶⁾.

Simple Vision Training You Can Do at Home

Here are some basic training exercises you can do without special equipment.

Pencil tracking (smooth pursuit practice): Hold a pen with your arm extended, and slowly move it up and down, left and right, and in circles while following the tip with your eyes only, without moving your head. Aim for 1–2 minutes per session, 2–3 sets per day.

Saccade practice: Mark two distant points on a wall and quickly shift your gaze between them without moving your head. Perform 50 round trips as one set, gradually increasing speed.

Peripheral vision awareness practice: While looking straight ahead, extend both arms to the sides and move your fingers to see how many you can recognize in your peripheral vision. Record the angle at which you can recognize them and compare periodically.

These are only supplementary self-training exercises; they are more effective when performed under professional evaluation and guidance.

Refractive Correction and Sports

• Contact lenses: Compared to glasses, they offer less visual field restriction and frame-induced distortion, which can be advantageous for maintaining visual function during sports ¹⁰⁾. However, depending on the sports environment, attention must be paid to dryness, foreign body contamination, and hygiene management.
• Protective eyewear (sports goggles)

Sports goggles with polycarbonate lenses (indirect ventilation protective eyewear)

Wishofflying. Empiral Vision Grey goggles. Wikimedia Commons. 2021. Figure 2. Source ID: File:Empiral_Vision_Grey_goggles.jpg. License: CC BY-SA 4.0.

A front-view photograph of indirect ventilation polycarbonate protective goggles with gray lenses, showing side ventilation holes and a design that accommodates prescription lenses. This corresponds to the protective eyewear (sports goggles) discussed in section “5. Vision Training and Visual Function Improvement.”

: Polycarbonate lenses have higher impact resistance than glass or regular plastic, significantly reducing the risk of eye injury. Compliance with ASTM F803 standard (American Society for Testing and Materials) is an indicator of safety ¹¹⁾.

• Refractive surgery (e.g., LASIK): Permanently corrects corneal shape, eliminating the need for contact lenses or glasses. Cases have been reported where it is applied to adult athletes with stable visual function ¹²⁾. Data from the U.S. Army refractive surgery program (2000–2003) confirmed the safety and efficacy of PRK and LASIK ¹²⁾.

Cautions Regarding Evidence for Vision Training

The effects of vision training vary among individuals, and because studies differ in target sports, measurement indicators, and training content, the quality of evidence is considered moderate ⁹⁾. Whether improvements in visual function indicators (e.g., DVA values, reaction time) directly lead to enhanced sports performance requires further verification. Some commercially advertised vision training devices lack sufficient scientific evidence, so it is recommended to verify the evidence before adoption.

Q Can vision training improve dynamic visual acuity?

A

Some studies have reported improvements in dynamic visual acuity and eye movements through training ⁹⁾. A study of youth field hockey players found that a sports vision training program improved multiple visual function indicators ⁹⁾. However, the degree of improvement varies among individuals, and evidence for a direct impact on athletic performance is limited. Continuous and systematic training along with professional feedback are considered important for enhancing effectiveness.

6. Physiological Basis of Visual Information Processing

Each component of sports vision is processed by different neural circuits.

Neural Basis of Dynamic Visual Acuity and Motion Perception

Perception of moving objects is mediated by the dorsal pathway (where/how pathway) from the primary visual cortex (V1) to visual area V5/MT (Middle Temporal area) ¹³⁾. Neurons in V5/MT respond selectively to motion direction and are involved in judging ball trajectories and opponent movement directions in sports. This pathway integrates with the ventral pathway (what pathway: responsible for object recognition) to process “what is moving, where, and how” as a whole ¹³⁾.

Neural Basis of Depth Perception (Stereopsis)

Stereopsis is established when binocular disparity detection neurons in V1 and V2 detect slight differences between the left and right retinal images and convert them into depth information ⁴⁾. Binocular stereopsis is more accurate than monocular depth cues, especially for distance judgments at close range (approximately 2 to 6 meters).

Neural Control of Eye Movements

Saccades are primarily controlled by the frontal eye fields (FEF) and superior colliculus, with precision and speed adjusted through coordination with the basal ganglia and cerebellum ⁸⁾. Smooth pursuit involves V5/MT and the vestibulo-ocular reflex pathway, determining the accuracy of tracking target velocity ⁸⁾. Eye movement control can be refined through practice, which is considered part of the training effect.

Age-Related Decline in Dynamic Visual Acuity

Dynamic visual acuity peaks in the 20s and 30s and declines with age ¹⁴⁾. A decrease in motion perception processing speed in V5/MT is thought to be a major factor ¹⁴⁾. Age-related nuclear sclerosis (changes in the lens), reduced contrast sensitivity, and slower eye movement speed also contribute to the decline in dynamic visual acuity. For masters athletes, these changes particularly affect athletic performance, making regular visual function assessment beneficial.

7. Latest Research and Future Perspectives

Note on Information at the Research Stage

The following content includes information that is at the research stage or early stages of practical application. It may not be available at all facilities currently and is provided as reference information for future technological and research developments.

Vision Training Using VR/AR

Sports vision training using VR (virtual reality) and AR (augmented reality) technology is in the research and development stage ¹⁵⁾. It features the ability to recreate sport-specific visual scenarios in a virtual environment and simultaneously train dynamic visual acuity, peripheral vision, and reaction time. A review of digital training technology (Appelbaum & Erickson, 2018) suggests that digital technologies including VR may be more efficient than traditional paper- and device-based training ¹⁵⁾.

Visual function assessment in e-sports

With the spread of competitive gaming (e-sports), attention to the visual function profile of e-sports players is increasing. Issues such as accommodative fatigue and eye strain from prolonged close use of high-resolution displays, as well as superior reaction time and eye movements, have become new subjects of sports vision research.

Wearable eye movement sensors

Research is progressing on wearing miniaturized and lightweight eye trackers during competition to measure eye movements in real time in actual game situations. By analyzing gaze patterns during competition, it is expected to clarify the visual basis of skill differences between experts and beginners and apply this to effective training design.

Reduction of visual reaction time through neurofeedback

Research is underway to improve visual attention and reaction time using technologies such as VR/AR, digital training, and neurofeedback. However, direct effects on competitive performance are still in the verification stage ¹⁾¹⁵⁾.

8. References

1. Buscemi A, Mondelli F, Biagini I, et al. Role of sport vision in performance: systematic review. J Funct Morphol Kinesiol. 2024;9(2):92.
2. Laby DM, Kirschen DG, Rosenbaum AL, et al. The effect of ocular dominance on the performance of professional baseball players. Ophthalmology. 1998;105(5):864-866.
3. Uchida Y, Kudoh D, Murakami A, et al. Origins of superior dynamic visual acuity in baseball players: superior eye movements or superior image processing. PLoS One. 2012;7(2):e31530.
4. Read JCA. Stereo vision and strabismus. Eye (Lond). 2015;29(2):214-224. doi:10.1038/eye.2014.279.
5. Laby DM, Appelbaum LG. Vision and on-field performance: a critical review of visual assessment and training studies with athletes. Optom Vis Sci. 2021;98(7):723-731.
6. Ando S, Kida N, Oda S. Central and peripheral visual reaction time of soccer players and nonathletes. Percept Mot Skills. 2001;92(3 Pt 1):786-794.
7. Owsley C, Sloane ME. Contrast sensitivity, acuity, and the perception of “real-world” targets. Br J Ophthalmol. 1987;71(10):791-796.
8. Land MF, McLeod P. From eye movements to actions: how batsmen hit the ball. Nat Neurosci. 2000;3(12):1340-1345.
9. Schwab S, Memmert D. The impact of a sports vision training program in youth field hockey players. J Sports Sci Med. 2012;11(4):624-631. PMID: 24150071. PMCID: PMC3763307.
10. Jones L, Efron N, Bandamwar K, et al. TFOS Lifestyle: impact of contact lenses on the ocular surface. Ocul Surf. 2023;29:175-219. doi:10.1016/j.jtos.2023.04.010.
11. Capao Filipe JA. Soccer (football) ocular injuries: an important eye health problem. Br J Ophthalmol. 2004;88(2):159-160.
12. Hammond MD, Madigan WP, Bower KS. Refractive surgery in the United States Army, 2000-2003. Ophthalmology. 2005;112(2):184-190.
13. Maunsell JH, Newsome WT. Visual processing in monkey extrastriate cortex. Annu Rev Neurosci. 1987;10:363-401.
14. Trick GL, Silverman SE. Visual sensitivity to motion: age-related changes and deficits in senile dementia of the Alzheimer type. Neurology. 1991;41(9):1437-1440.
15. Appelbaum LG, Erickson G. Sports vision training: a review of the state-of-the-art in digital training techniques. Int Rev Sport Exerc Psychol. 2018;11(1):160-189.