The Peli Lens uses high powered prisms placed in the peripheral vision to expand a hemianopic patient’s awareness of their blind side by over 30 degrees when using the 57 diopter Peli Lens.
Where The Prisms Go
The prisms are placed 6 millimeters above and below the pupil on same side as the hemianopia. (Left hemianopsia = prisms on left eye, right hemianopia = prisms on right eye)
What the Field Expansion Looks Like
Most patients describe the expanded field as a “ghost image.”
Full Visual Field
Hemianopsia Visual Field
Expanded field with ghost image
Reacting to the Information from the Expanded Field
The information in the expanded field can be viewed by the patient moving their eyes or moving their head to focus on that area.
Adapting to Peli Peripheral Prisms
This ghost image field expansion does take some getting used to. Patients often experience some difficulties differentiating their regular field from the expanded field. It is recommended that a patient wear the prisms for six weeks, and go through some self-training exercises to help with adaptation.
Success Rate of the Peli Prism
In the initial trial of the Peli Peripheral Prisms, 74% wished to continue wear after the 6-week assessment. At the end of the first year, 47% of patients continued to wear the prisms. Many doctors have reported success rates much higher than this when the fitting is coupled with multiple training sessions.