The Effects of Rotational Prisms on Badminton Players' Ocular Vergence Training and Enhancement of Shot Accuracy

Summary

This randomized controlled trial is designed to investigate whether a novel visual training system can improve eye coordination, reaction time, and hitting accuracy in competitive badminton players. The training utilizes a device called the Automatic Dual Rotational Risley Prisms (ADRRPs), which presents alternating base-in and base-out prism demands to stimulate vergence eye movements. This type of training aims to enhance the eyes' ability to converge and diverge quickly and accurately-a function that is important for visual clarity and motor performance during fast-paced sports.

A total of 26 collegiate badminton athletes aged 18 to 25 years will be recruited from two universities in Taiwan. Participants will be randomly assigned to one of two groups: a visual training group using the active ADRRPs system, and a control group using a sham version of the same device containing plano lenses (with no prism effect). Training will be delivered twice per week for four weeks, with each session lasting 15 minutes. During each session, participants will view a video while the device applies alternating prism stimulation based on each individual's pre-measured fusional vergence capacity.

Outcome measures will be assessed at baseline and after the four-week training period. These include vergence facility (cycles per minute), accommodative facility (flipper test), near point of convergence, and positive fusional vergence at near. Reaction time will be measured using a light-based agility task with BlazePod sensors, and hitting performance will be evaluated using a shuttlecock launcher that delivers randomized targets to various court zones.

All participants will be monitored for any adverse events, and any symptoms such as diplopia, dizziness, or discomfort will be documented. Data will be analyzed as described in the Statistical Analysis Plan.

Conditions

• Eye Movements
• Visual Perception
• Psychomotor Performance
• Sports

Interventions

DEVICE

Arm 1 - Experimental Group Intervention Name: ADRRPs Vergence Training Intervention Description: Participants wore an Automatic Dual Rotational Risley Prism (ADRRPs) headset to perform vergence eye

ADRRPs Vergence Training Intervention Description: Participants wore an ADRRPs headset that applied alternating base-in and base-out prism power to stimulate vergence eye movements. Prism levels were customized based on each participant's fusional vergence. Training was performed twice weekly for 15 minutes over four weeks while viewing a near video target. Sham Visual Training with Plano Lenses Intervention Description: Participants wore an identical ADRRPs headset fitted with plano lenses that produced no prism effect. The procedure and schedule matched the experimental group but provided no vergence stimulation, serving as a sham control.

DEVICE

1. Experimental Group Intervention Name: ADRRPs-Based Vergence Training; 2. Control Group Intervention Name: Sham Training with Plano Lenses.

ADRRPs-Based Vergence Training This intervention used the Automatic Dual Rotational Risley Prisms (ADRRPs) system to deliver alternating base-in and base-out prism stimulation for vergence training. Prism levels were customized based on each participant's fusional vergence. Training was conducted twice per week for four weeks, 15 minutes per session, while participants viewed a near video target. This protocol provides automated and symmetric vergence demand, distinguishing it from conventional near-point or static prism exercises. Sham Training with Plano Lenses Participants used the same ADRRPs headset as the experimental group but with plano lenses that produced no prism effect. The training schedule and visual tasks matched the experimental condition, but no vergence stimulus was applied. This design enabled participant masking while providing no active optical stimulation, serving as a sham comparator distinct from both active training and no-treatment controls.

Sponsors & Collaborators

• China Medical University Hospital

  lead OTHER

Principal Investigators

• Hsuan-Yu Huang, Ph.D. · College of Health Sciences, Central Taiwan University of Science and Technology

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

25 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-03-24

Primary Completion

2025-05-30

Completion

2025-05-30

Countries

• Taiwan

Study Locations