Testing prism glasses to help expand vision for patients with visual field loss

Visual Field Expansion Through Innovative Multi-Periscopic Prism Design

Not applicable Interventional Massachusetts Eye and Ear Infirmary · NCT04424979

This study is testing special prism glasses to see if they can help people with vision loss, like those with hemianopia or tunnel vision, see more of their surroundings.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment20 (estimated)
Ages7 Years to 80 Years
SexAll
SponsorMassachusetts Eye and Ear Infirmary Academic / other
Locations1 site (Boston, Massachusetts)
Trial IDNCT04424979 on ClinicalTrials.gov

What this trial studies

This study aims to develop and evaluate various configurations of high-power prisms designed to expand the visual field of patients suffering from visual field loss. Participants will undergo multiple visits to the Schepens Eye Research Institute for fitting and testing of the prism glasses. The goal is to identify the most effective designs and fitting parameters that can be used in future clinical applications. The study focuses on improving obstacle detection for individuals with conditions such as hemianopia and tunnel vision.

Who should consider this trial

Good fit: Ideal candidates include individuals with visual field loss who have a visual acuity of at least 20/50 in their better eye and can walk independently.

Not a fit: Patients with cognitive dysfunction, balance problems, or those who have had seizures in the last six months may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly enhance the mobility and safety of patients with visual field loss.

How similar studies have performed: While the use of prisms for visual field expansion has been explored, this specific configuration testing is a novel approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Visual field loss, either peripheral field loss or hemianopic field loss
* Visual acuity of at least 20/50 in the better eye
* In sufficiently good health to be able to complete sessions lasting 2-4 hours
* Able to independently walk short distances
* Able to give voluntary, informed consent
* Able to speak English

Exclusion Criteria:

* Any physical or mental impairments, including cognitive dysfunction, balance problems or other deficits that could impair the ability to walk or use the prism spectacles
* A history of seizures in the last 6 months
* Hemispatial neglect (subjects with hemianopic field loss only)

Where this trial is running

Boston, Massachusetts

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Hemianopia, HomonymousTunnel VisionVisual Field Defect, PeripheralVisual Field Constriction BilateralVisual Field Defect Homonymous BilateralVisual field expansionPrismsHemianopsia
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.