Brock String
Brock String is an ophthalmic vision-training tool consisting of a cord with beads spaced along its length. During convergence exercises, a person fixates on different beads while observing…
Brock String is an ophthalmic vision-training tool consisting of a cord with beads spaced along its length. During convergence exercises, a person fixates on different beads while observing how the visual axes align and where the cord appears to cross.
The string provides a simple physical reference for binocular eye-movement coordination and convergence practice. It is a training tool, not an electronic measurement instrument.
Visual Alignment
When fixation shifts among beads, the perceived crossing of the string provides a visible cue about how the eyes are converging. The bead locations create distinct fixation points along one line of sight.
Gulden describes the Brock String for binocular vision exercises.
Who Else Makes It
Concentrated in Jiangsu (1), Guangdong (1), Beijing (1). One is registered as a contract manufacturer, able to build to a specification.
| Manufacturer | City | Province | Registered as | Device types |
|---|---|---|---|---|
| Wuxi Zontai Int’l Corporation Ltd. | Wuxi | Jiangsu | Contract manufacturer | 22 |
| Shenzhen Kaiyan Medical Equipment Co., Ltd. | Shenzhen | Guangdong | Contract manufacturer | 17 |
| Beijing Mingren Shikang Technology Co., Ltd. | Beijing | Beijing | Manufacturer | 1 |
Record
| Listed by | Gulden Ophthalmics, United States |
|---|---|
| FDA product code | NXR |
| Device type | Fixation, Vision Training, Binocular |
| Device class | Class 1 |
| Regulation | 21 CFR 886.1290 |
| Establishment | Specification developer, Repacker / relabeller, Complaint-file establishment, Manufacturer |
| Premarket notification | Exempt |
| Record published | 2023-07-05 |
Specifications
| MRI safety | Labeling does not contain MRI Safety Information |
|---|---|
| Label carries | lot or batch number, manufacturing date |
Catalogue Numbers
| Catalogue number | Size | Status |
|---|---|---|
| 1 | In distribution |
Same Product Code
| Product | Sold by | Catalogue numbers |
|---|---|---|
| Fresnel Prism AND Lens | Fresnel Prism & Lens Co. | 2 |
| Otus® Fixation, Vision Training, Binocular | Edenlux Corp. | 1 |
| NeuroEyeCoach | Novavision, Inc. | 1 |
Source: U.S. FDA establishment registration and device listing records, public domain. Restructured for clarity and searchability. Not affiliated with or endorsed by the FDA. Records are records: nothing here is an offer of sale.