Distance horizontal fusional vergence facility (DFF) is often found to be reduced in many post-concussion patients. Dr. Barry Tannen has extensively studied this issue and developed a simple, yet effective test that doubles as a training tool for addressing this common challenge.

Introducing the specialised prism flipper, featuring 2PD Base-In (BI) on one side and 4PD Base-Out (BO) on the other. The flipper package includes a distance target and comprehensive instructions for effectively testing your patients. For your convenience, a quick reference guide is also printed on the back of the laminated target card.

Utilise these innovative prism flippers to:

1. Assist in diagnosing distance fusional instability
2. Monitor the recovery progress of distance fusional instability
3. Aid in training and improving distance fusional facility

Kit Includes:

• Bernell Custom Prism Flipper with (2) 1PD Base-In Lenses (2PD Range) on one side and (2) 2PD Base-Out Lenses (4PD Range) on the other side
• Laminated Target Card with letter sized for 15ft testing distance plus Quick Instruction Guide on back
• Instruction Sheet
  

Research Articles:

Tannen, B., Rogers, J., Ciuffreda, K. J., Lyons, E., & Shelley-Tremblay, J. (2016). Distance Horizontal Fusional Facility (DFF): A Proposed New Diagnostic Test for Concussion Patients. Vision Development & Rehabilitation, 2(3), 170-175. Click here to read the article