--- product_id: 55273442 title: "Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility" brand: "brock string" price: "€ 23.22" currency: EUR in_stock: true reviews_count: 13 category: "Brock String" url: https://www.desertcart.be/products/55273442-brock-string-vision-convergence-insufficiency-training-tool-for-eye-muscle store_origin: BE region: Belgium --- # 3 x 6-ft precision strings Durable nylon/polypropylene build 5 adjustable beads per string Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility **Brand:** brock string **Price:** € 23.22 **Availability:** βœ… In Stock ## Summary > πŸ‘οΈβ€πŸ—¨οΈ Sharpen your vision, dominate your game! ## Quick Answers - **What is this?** Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility by brock string - **How much does it cost?** € 23.22 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.be](https://www.desertcart.be/products/55273442-brock-string-vision-convergence-insufficiency-training-tool-for-eye-muscle) ## Best For - brock string enthusiasts ## Why This Product - Trusted brock string brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Premium Durability:** Crafted from high-quality nylon and polypropylene for long-lasting, reliable performance. - β€’ **Effortless Home Use:** Quick setup and intuitive design mean you can train anytime, anywhereβ€”no coach needed. - β€’ **Proven Vision Improvement:** Join thousands who’ve enhanced eye strength and reduced double vision with guided exercises. - β€’ **Elite Eye Muscle Conditioning:** Train convergence insufficiency and sharpen focus with pro-grade Brock Strings. - β€’ **Sport-Specific Precision Training:** Optimize your athletic edge by simulating real-game eye positions effortlessly. ## Overview The Vision Convergence Insufficiency Training Tool features three 6-foot Brock Strings, each with five tightly fitted beads, designed to strengthen eye muscles and improve focus. Made from durable nylon and polypropylene, this tool is ideal for athletes and professionals seeking enhanced visual performance and convergence training from the comfort of home. Backed by over 2,000 positive reviews, it’s a trusted solution for vision training and sports-specific eye agility. ## Description Product description Review: Good quality, easy to use - It's good. The beads slide easily but stay where you put them. The string is easy to tie and untie. The string can be drawn taunt and bounce is easily controlled. Review: Great for eye convergence - This string provides a means to work on convergence problems. I have excellent vision in my eyes but when I'm tired etc. I start seeing double --especially watching the television. I can see improvement after just a few sessions of the exercises. Hopefully before long I will no longer have the problem. Comes with instructions in English! They just don't indicate how long one should do them. If you get one, practice at least a few minutes at a time. ## Features - ENHANCE CONVERGENCE AND FOCUS: Use the Brock String convergence training tool to strengthen eye muscles, focus, and support visual performance for daily activities and sports - BOOST ATHLETIC PERFORMANCE: The Brock eye string allows precise eye training in sport-specific positions, giving you a competitive edge and enhanced visual coordination - EASY-TO-USE EYE EXERCISE TOOL: Simple setup and short learning curve let you practice convergence and eye focus exercises at home, making vision training convenient for beginners and advanced users - PREMIUM FOCUS STRING WITH BALLS: Crafted with durable string and high-quality beads, this eye muscle strengthening tool ensures long-lasting use and consistent performance for repeated vision exercises - FRONT SIGHT TOOL WITH INSTRUCTIONS INCLUDED: Comes with clear guidance and tips for proper use, ensuring effective training and helping you get the most from your Brock String sessions ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B075881G1K | | Best Sellers Rank | #20,983 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #4,206 in Shooting #4,705 in Hunting Equipment | | Brand | Brock String | | Brand Name | Brock String | | Color | Blue, Green, Red | | Customer Reviews | 4.5 out of 5 stars 2,122 Reviews | | Grip Material | Nylon or Polypropylene | | Handle Material | Nylon or Polypropylene | | Item Length | 72 Inches | | Item Weight | 0.04 Kilograms | | Manufacturer | Thera Systems LLC | | Material | Nylon, Polypropylene (PP) | | Model Number | 5Q-N5NL-FZO4 | | Other Special Features of the Product | Convergence Training | | Part Number | 5Q-N5NL-FZO4 | | Recommended Uses For Product | Vision Training, Convergence Insufficiency, Strength and Athletic Performance, Sports Performance | | Special Feature | Convergence Training | | Target Audience | Adult | | UPC | 860007923098 722512369382 | ## Product Details - **Brand:** Brock String - **Material:** Nylon, Polypropylene (PP) - **Recommended Uses For Product:** Vision Training, Convergence Insufficiency, Strength and Athletic Performance, Sports Performance - **Special Feature:** Convergence Training - **Target Audience:** Adult ## Images ![Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility - Image 1](https://m.media-amazon.com/images/I/51i-qwxd9HL.jpg) ![Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility - Image 2](https://m.media-amazon.com/images/I/61sBJaJtdXL.jpg) ![Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility - Image 3](https://m.media-amazon.com/images/I/51dsMZYiYtL.jpg) ![Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility - Image 4](https://m.media-amazon.com/images/I/61diUmT6sBL.jpg) ![Brock String, Vision Convergence Insufficiency Training Tool for Eye Muscle Strengthening, Focus Exercise and Agility - Image 5](https://m.media-amazon.com/images/I/61dDl7K1JEL.jpg) ## Available Options This product comes in different **Size, Style** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Good quality, easy to use *by J***B on December 2, 2025* It's good. The beads slide easily but stay where you put them. The string is easy to tie and untie. The string can be drawn taunt and bounce is easily controlled. ### ⭐⭐⭐⭐⭐ Great for eye convergence *by C***D on January 7, 2026* This string provides a means to work on convergence problems. I have excellent vision in my eyes but when I'm tired etc. I start seeing double --especially watching the television. I can see improvement after just a few sessions of the exercises. Hopefully before long I will no longer have the problem. Comes with instructions in English! They just don't indicate how long one should do them. If you get one, practice at least a few minutes at a time. ### ⭐⭐⭐⭐⭐ Great quality, great product *by J***C on February 6, 2019* I read a lot of reviews that mentioned the beads being loose on the string, but I did not find that to be the case. The string is good quality and the beads fit well and stay in place, yet are easy to position. The item comes with directions and I received an email from the seller with a pdf of the same sheet, which I appreciated. My only issue is that my eyes freakin suck! I have a prism of 21 in my glasses, an extreme case of diplopia. I don't have "googly eyes (what my wife teases me about), but they just don't like working together as they tend to act esotropic. I am somewhat discouraged that I simply cannot see a single image of a bead if it is positioned more than 5 inches from my face. The directions provided do not provide any guidance for this issue but I was able to find some tips on other internet sources. If anyone else has the same issue, use an index card to cover your dominant eye and focus hard on the bead with the other eye. Slowly remove the index card and it can help bring the two images of the bead closer together. Alternatively, simply closing your eyes for a second can bring them close as well. I realize this item isn't necessarily sold to treat a medical condition, but perhaps the seller can add these tips in for sports use? All in all, fantastic product and great customer support! ## Frequently Bought Together - Brock String Front Sight Focus String Combo Pack, Three 6-Foot, Vision Convergence Training Tool, Great for Shooters, Front Sight Training and More! - SADIKALO 6Pcs Eye Exercise Chart - Visual Muscle Relaxation Office Classroom Wall Decor Myopia Dry Eye Office Gifts Waterproof Posters Card Desk Sign for Home School Kids Students Office Coworkers - Brock String - Vision Convergence Training - Convergence Insufficiency Tool - Train Vision, Athletic Performance, and More!, White, 6 foot --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.be/products/55273442-brock-string-vision-convergence-insufficiency-training-tool-for-eye-muscle](https://www.desertcart.be/products/55273442-brock-string-vision-convergence-insufficiency-training-tool-for-eye-muscle) --- *Product available on Desertcart Belgium* *Store origin: BE* *Last updated: 2026-05-28*