Eye Dominance-based Visual TrainingNCT07899970
Eye Dominance-based Visual Training
A study testing Eye Dominance-Based Visual Training and Standard Volleyball Warm-up in people with Eye Dominance-based Visual Training and Volleyball Players, run by Istinye University.
Trial summary
Eye dominance refers to the preference for one eye when processing visual information and may influence visual-motor integration and motor coordination. In volleyball, where rapid decision-making, accurate target tracking, and precise hand-eye coordination are essential, visual processing plays a critical role in… Read more about this study
- Who is it for?
- Ages 18 to 30 yearsHealthy volunteers can take part
- Conditions the study is for
- Eye Dominance-based Visual Training, Volleyball Players
- What is being tested?
- Eye Dominance-Based Visual Training and Standard Volleyball Warm-up
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- No sites listed yet
- Study dates
- 30 Nov 2026to 5 Mar 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Competitive male or female volleyball players aged 18-30 years
- Regular volleyball training at least twice a week
- At least 1 year of volleyball experience and holding a licensed athlete status
- No upper extremity injury or neurological disorder in the last 6 months
- Normal or corrected-to-normal vision
- Willingness to participate voluntarily and to provide written informed consent
- Dominant eye clearly identifiable with the Miles test
Who cannot join
- Upper extremity injury or surgery in the last 6 months
- Use of systemic or local medication that may affect neuromuscular performance
- Diagnosed musculoskeletal or neurological disorders that may adversely affect motor performance
- Visual impairments or other ophthalmological problems that may interfere with eye dominance training
About this study
Official title: The Acute Effects of Eye Dominance-Based Visual Training on Upper Extremity Motor Performance in Volleyball Players
Eye dominance refers to the preference for one eye when processing visual information and may influence visual-motor integration and motor coordination. In volleyball, where rapid decision-making, accurate target tracking, and precise hand-eye coordination are essential, visual processing plays a critical role in upper extremity performance. Although previous studies have investigated eye dominance and visual training in relation to motor control and athletic performance, evidence regarding their acute effects in volleyball players remains limited. This study aims to investigate the acute effects of eye dominance-based visual training on upper extremity motor performance in volleyball players. By evaluating a single-session, low-cost, and equipment-minimal visual training protocol, the study seeks to determine whether targeted visual exercises can produce measurable improvements in motor performance. The findings may contribute to the development of individualized visual-motor training strategies to support athletic performance and inform future research in sports science, physiotherapy, and motor control.
Read the detailed description
Eye dominance refers to the tendency of the brain to rely more heavily on visual information from one eye than the other. Similar to hand dominance, eye dominance may influence visual processing, spatial awareness, and visual-motor coordination. However, dominant eye and dominant hand do not always occur on the same side, a condition known as cross-dominance. Previous research has suggested that the relationship between eye and hand dominance may be relevant to motor coordination and performance, highlighting the importance of individualized approaches to assessing visual-motor function in sports.
Stereoscopic vision, which enables depth perception through the integration of visual information from both eyes, is essential for accurately estimating distances, tracking moving objects, and responding to dynamic environments. These abilities are particularly important in volleyball, a sport characterized by rapid ball movement, frequent changes in player positioning, and the need for precise timing and quick decision-making. Technical skills such as serving, passing, blocking, and spiking require effective visual tracking, rapid reactions, and accurate upper extremity movements. Therefore, visual processing and visual-motor integration may contribute to upper extremity motor performance in volleyball players.
Previous studies in optometry, neuroscience, and sports science have examined eye dominance, binocular vision, visual processing, and their potential relationships with motor control and athletic performance. Research on visual training has also suggested that targeted exercises may improve selected visual performance parameters, including dynamic visual acuity, balance, reaction time, and visual-motor coordination. Furthermore, the integration of visual information with proprioceptive input is important for the precise control of upper extremity movements. These factors may be particularly relevant to volleyball players, who repeatedly perform high-velocity overhead movements and are susceptible to shoulder and other upper extremity overuse injuries. However, evidence regarding the immediate effects of eye dominance-based visual training on upper extremity motor performance in volleyball players remains limited.
The aim of this study is to investigate the acute effects of eye dominance-based visual training on upper extremity motor performance in volleyball players. The study will focus on whether a single session of targeted visual exercises can produce measurable changes in motor performance. Unlike training programs that require repeated sessions over several weeks, the proposed protocol is designed to be brief, practical, low-cost, and feasible to implement in sports settings with minimal equipment. By examining the immediate responses to visual training, this study seeks to contribute to the understanding of the potential relationship between eye dominance, visual-motor integration, and upper extremity motor performance.
The findings may provide preliminary evidence regarding the potential value of incorporating individualized visual exercises into volleyball training and physiotherapy practice. In addition, the study may help inform the development of personalized visual-motor training strategies tailored to athletes' visual dominance characteristics and performance needs. Further research may build on these findings to investigate the effects of repeated training sessions, the long-term retention of potential improvements, and the transfer of changes in motor performance to sport-specific skills.
- Being tested
- Eye Dominance-Based Visual Training, Standard Volleyball Warm-up
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Eye Dominance-Based Visual TrainingBehavioural
Behavioral: Eye Dominance-Based Visual Training A single-session visual training protocol performed after the dominant eye is identified with the Miles test. It has five stations: (1) eye massage and palming for 30-60 seconds; (2) a letter saccade station, with fast shifts between letter charts, reading aloud and directional responses; (3) an anti-saccade station, with a response opposite to a colored cue, followed by receiving or passing a volleyball; (4) a Brock string station, with focusing on colored beads, followed by ball control or passing; (5) dynamic gaze stabilization, with fixation on colored targets while the eyes and the head/arm move in opposite directions. Each station is done for 3 sets of 10-15 repetitions, separately for the dominant and non-dominant eye.
Arm: Eye Dominance Training Group
Standard Volleyball Warm-upBehavioural
The standard volleyball warm-up routine that is normally done before training. Arms: Eye Dominance Training Group, Control Group
| Study group | Role | What they receive |
|---|---|---|
| Eye Dominance Training Group | Experimental | Participants complete the standard volleyball warm-up plus a single session of eye dominance-based visual training. The total session duration is matched to the control group. Receives: Behavioral: Eye Dominance-Based Visual Training |
| Control Group | Active comparator | Participants complete only the standard volleyball warm-up, with a total duration equal to that of the experimental group. Receives: Behavioral: Standard Volleyball Warm-up |
What is being measured
The primary outcome is the main question the study is designed to answer.
Seated Medicine Ball Throw Distance
Upper body explosive power is assessed with the seated overhead medicine ball throw test. The participant sits with the back against a wall and the legs extended, then throws a 2-kg medicine ball. The distance from the wall to the landing point is measured in centimeters. The test is done three times and the best throw is recorded.
Measured: Baseline (pre-intervention) and immediately after the single intervention session
Nelson Hand Reaction Time
Visual-motor reaction time is assessed with the Nelson Hand Reaction Test. The participant sits with the dominant elbow resting on a table and catches a vertically dropped ruler released without warning. The catch distance (cm) is recorded over five trials. The highest and lowest values are discarded and the remaining three are averaged. Reaction time is calculated as t = √(2d/g).
Measured: Baseline (pre-intervention) and immediately after the single intervention session
Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) Score
Upper extremity stability and shoulder girdle neuromuscular control are assessed with the Closed Kinetic Chain Upper Extremity Stability Test. In a push-up position (modified for females) with the hands 90 cm apart, the participant alternately touches the opposite hand for 15 seconds. The test is done three times with 45-second rest intervals, and the mean number of touches is recorded.
Measured: Baseline (pre-intervention) and immediately after the single intervention session
Scapular Muscle Endurance Test (SMET) Holding Time
The endurance of the middle and lower trapezius and rhomboid muscles is assessed with the Scapular Muscle Endurance Test. Facing a wall, with the elbows flexed to 90° and a bar placed between the elbows, the participant applies 1 kg of external rotation force to a dynamometer and holds the position as long as possible. The test ends if the bar falls, 90° elbow flexion is lost, or discomfort occurs. The best holding time (seconds) from two trials is recorded.
Measured: Baseline (pre-intervention) and immediately after the single intervention session
Eye Dominance Determined by the Miles Test
Eye dominance is determined with the Miles test. With arms extended, the participant forms a triangle with the thumbs and index fingers and, with both eyes open, focuses on a target about 3 meters away. The eyes are then closed one at a time; the eye that keeps the target aligned within the triangle is recorded as dominant (right/left). The test is done under controlled indoor lighting.
Measured: Baseline (before the intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Oct 2026
- Study start30 Nov 2026 (estimated)
- Primary completion25 Feb 2027 (estimated)
- Study completion5 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Eye Dominance-based Visual TrainingStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Istinye University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Beyza Tanrıöğen, Istinye University
- Investigators
- Beyza Tanrıöğen, Study director, Istinye University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07899970
- Sponsor's protocol ID
- Istinye BT 4
- Status last verified
- Oct 2026
- First submitted
- 21 Oct 2026
- Last updated
- 28 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Acute Effects of Eye Dominance-Based Visual Training on Upper Extremity Motor Performance in Volleyball Players
- ClinicalTrials.gov ID
- NCT07899970
- Acronym / sponsor ID
- Istinye BT 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Istinye UniversityUniversity, hospital or other
- Study start
- 30 Nov 2026 (estimated)
- Primary completion
- 25 Feb 2027 (estimated)
- Study completion
- 5 Mar 2027 (estimated)
- First posted
- 28 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Eye dominance refers to the preference for one eye when processing visual information and may influence visual-motor integration and motor coordination. In volleyball, where rapid decision-making, accurate target tracking, and precise hand-eye coordination are essential, visual processing plays a critical role in upper extremity performance. Although previous studies have investigated eye dominance and visual training in relation to motor control and athletic performance, evidence regarding their acute effects in volleyball players remains limited. This study aims to investigate the acute effects of eye dominance-based visual training on upper extremity motor performance in volleyball players. By evaluating a single-session, low-cost, and equipment-minimal visual training protocol, the study seeks to determine whether targeted visual exercises can produce measurable improvements in motor performance. The findings may contribute to the development of individualized visual-motor training strategies to support athletic performance and inform future research in sports science, physiotherapy, and motor control.
Detailed description
Eye dominance refers to the tendency of the brain to rely more heavily on visual information from one eye than the other. Similar to hand dominance, eye dominance may influence visual processing, spatial awareness, and visual-motor coordination. However, dominant eye and dominant hand do not always occur on the same side, a condition known as cross-dominance. Previous research has suggested that the relationship between eye and hand dominance may be relevant to motor coordination and performance, highlighting the importance of individualized approaches to assessing visual-motor function in sports.
Stereoscopic vision, which enables depth perception through the integration of visual information from both eyes, is essential for accurately estimating distances, tracking moving objects, and responding to dynamic environments. These abilities are particularly important in volleyball, a sport characterized by rapid ball movement, frequent changes in player positioning, and the need for precise timing and quick decision-making. Technical skills such as serving, passing, blocking, and spiking require effective visual tracking, rapid reactions, and accurate upper extremity movements. Therefore, visual processing and visual-motor integration may contribute to upper extremity motor performance in volleyball players.
Previous studies in optometry, neuroscience, and sports science have examined eye dominance, binocular vision, visual processing, and their potential relationships with motor control and athletic performance. Research on visual training has also suggested that targeted exercises may improve selected visual performance parameters, including dynamic visual acuity, balance, reaction time, and visual-motor coordination. Furthermore, the integration of visual information with proprioceptive input is important for the precise control of upper extremity movements. These factors may be particularly relevant to volleyball players, who repeatedly perform high-velocity overhead movements and are susceptible to shoulder and other upper extremity overuse injuries. However, evidence regarding the immediate effects of eye dominance-based visual training on upper extremity motor performance in volleyball players remains limited.
The aim of this study is to investigate the acute effects of eye dominance-based visual training on upper extremity motor performance in volleyball players. The study will focus on whether a single session of targeted visual exercises can produce measurable changes in motor performance. Unlike training programs that require repeated sessions over several weeks, the proposed protocol is designed to be brief, practical, low-cost, and feasible to implement in sports settings with minimal equipment. By examining the immediate responses to visual training, this study seeks to contribute to the understanding of the potential relationship between eye dominance, visual-motor integration, and upper extremity motor performance.
The findings may provide preliminary evidence regarding the potential value of incorporating individualized visual exercises into volleyball training and physiotherapy practice. In addition, the study may help inform the development of personalized visual-motor training strategies tailored to athletes' visual dominance characteristics and performance needs. Further research may build on these findings to investigate the effects of repeated training sessions, the long-term retention of potential improvements, and the transfer of changes in motor performance to sport-specific skills.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Eye Dominance Training Group | Experimental | Behavioral: Eye Dominance-Based Visual TrainingParticipants complete the standard volleyball warm-up plus a single session of eye dominance-based visual training. The total session duration is matched to the control group. |
| Control Group | Active comparator | Behavioral: Standard Volleyball Warm-upParticipants complete only the standard volleyball warm-up, with a total duration equal to that of the experimental group. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Competitive male or female volleyball players aged 18-30 years
- Regular volleyball training at least twice a week
- At least 1 year of volleyball experience and holding a licensed athlete status
- No upper extremity injury or neurological disorder in the last 6 months
- Normal or corrected-to-normal vision
Key exclusion criteria (4 listed)
- Upper extremity injury or surgery in the last 6 months
- Use of systemic or local medication that may affect neuromuscular performance
- Diagnosed musculoskeletal or neurological disorders that may adversely affect motor performance
- Visual impairments or other ophthalmological problems that may interfere with eye dominance training
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Eye Dominance-Based Visual TrainingBehavioral: Eye Dominance-Based Visual Training A single-session visual training protocol performed after the dominant eye is identified with the Miles test. It has five stations: (1) eye massage and palming for 30-60 seconds; (2) a letter saccade station, with fast shifts between letter charts, reading aloud and directional responses; (3) an anti-saccade station, with a response opposite to a colored cue, followed by receiving or passing a volleyball; (4) a Brock string station, with focusing on colored beads, followed by ball control or passing; (5) dynamic gaze stabilization, with fixation on colored targets while the eyes and the head/arm move in opposite directions. Each station is done for 3 sets of 10-15 repetitions, separately for the dominant and non-dominant eye. Arm: Eye Dominance Training Group | Behavioural | Eye Dominance Training Group |
| Standard Volleyball Warm-upThe standard volleyball warm-up routine that is normally done before training. Arms: Eye Dominance Training Group, Control Group | Behavioural | Control Group |
Primary outcome
Seated Medicine Ball Throw Distance
Time frame: Baseline (pre-intervention) and immediately after the single intervention session
Upper body explosive power is assessed with the seated overhead medicine ball throw test. The participant sits with the back against a wall and the legs extended, then throws a 2-kg medicine ball. The distance from the wall to the landing point is measured in centimeters. The test is done three times and the best throw is recorded.
Nelson Hand Reaction Time
Time frame: Baseline (pre-intervention) and immediately after the single intervention session
Visual-motor reaction time is assessed with the Nelson Hand Reaction Test. The participant sits with the dominant elbow resting on a table and catches a vertically dropped ruler released without warning. The catch distance (cm) is recorded over five trials. The highest and lowest values are discarded and the remaining three are averaged. Reaction time is calculated as t = √(2d/g).
Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) Score
Time frame: Baseline (pre-intervention) and immediately after the single intervention session
Upper extremity stability and shoulder girdle neuromuscular control are assessed with the Closed Kinetic Chain Upper Extremity Stability Test. In a push-up position (modified for females) with the hands 90 cm apart, the participant alternately touches the opposite hand for 15 seconds. The test is done three times with 45-second rest intervals, and the mean number of touches is recorded.
Scapular Muscle Endurance Test (SMET) Holding Time
Time frame: Baseline (pre-intervention) and immediately after the single intervention session
The endurance of the middle and lower trapezius and rhomboid muscles is assessed with the Scapular Muscle Endurance Test. Facing a wall, with the elbows flexed to 90° and a bar placed between the elbows, the participant applies 1 kg of external rotation force to a dynamometer and holds the position as long as possible. The test ends if the bar falls, 90° elbow flexion is lost, or discomfort occurs. The best holding time (seconds) from two trials is recorded.
Eye Dominance Determined by the Miles Test
Time frame: Baseline (before the intervention)
Eye dominance is determined with the Miles test. With arms extended, the participant forms a triangle with the thumbs and index fingers and, with both eyes open, focuses on a target about 3 meters away. The eyes are then closed one at a time; the eye that keeps the target aligned within the triangle is recorded as dominant (right/left). The test is done under controlled indoor lighting.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2026.
- Individual participant dataSharing planned: Undecided
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Beyza Tanrıöğen study director
Istinye University
Questions about this trial
What is this clinical trial studying?
A study testing Eye Dominance-Based Visual Training and Standard Volleyball Warm-up in people with Eye Dominance-based Visual Training and Volleyball Players, run by Istinye University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 28 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Seated Medicine Ball Throw Distance (time frame: Baseline (pre-intervention) and immediately after the single intervention session). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2026.