New Developments



 Patients should first be fit with the 40∆ Peli Press-on Prisms and wear them for a month.  After the trial period,  the patient and doctor can decide whether an upgrade into the Peli Lens glasses in the 40∆ or either of the 57∆ designs is appropriate, depending on the patient’s lifestyle and goals.

The following pictures show the various Peli Lens™ prism designs and their visual effects when viewed through the Peli Lens.  In this case, the prisms are placed on the right lens of a right Hemianope. No prisms are placed on the left eye, so the hemianope has a full range of hemianopic vision in the left eye. 

The 40Δ Peli Press-on Prisms can be fit by any eye care professional by following the instructions in the Peli Lens Fitting Kit.  It is the most economical, simple, and effective method of increasing the visual field of hemianopic patients by 20º.  There is also published research available on the  40Δ Horizontal reporting a 74% patient acceptance rate.  We are highly confident that any eye care professional can fit the 40Δ Horizontal if the step-by-step instructions in the Peli Lens Fitting Kit are followed.  The 40Δ Horizontal prisms offer easier care and clearer images.

The 57Δ Peli Lens Horizontal glasses can be ordered after the 40∆ Horizontal Peli Press-on Prisms have been tried and have proven beneficial.   The 57Δ Horizontal Peli Lens offers 50% more visual field expansion (30º)  than the 40Δ Horizontal Peli Lens.  Prescribing the 57Δ Horizontal Peli Lens is indicated if the 40∆ Horizontal Peli Press-on Prisms do not give the patient the field expansion required for certain tasks and goals.


There is one Peli Lens™ style available in the Peli Press-on Prism.  This is the 40Δ Horizontal Peli Press-on Prism which offers 20˚ field expansion. It is a low cost method of determining patient adaptation to the Peli concept.  Although the Peli Press-on Prisms are as effective as the 40Δ Peli Lens glasses for mobility they do have drawbacks.  They yellow with age and can fall off or shift position on the glasses causing repeat visits to the eye care professional for re-fitting.  Most patients who have the Peli Lens glasses prefer them for their superior optical clarity and ease of care.


There are three Peli Lens™ glasses styles:

· · 40∆ Horizontal, offering the same field expansion of 20º as the Peli Press-on prisms.

· · 57∆ Horizontal offering 30º of field expansion.

· · 57∆ Oblique allowing the view of objects at midline but reducing the field expansion to about 27º.

Room as seen by a fully sighted person.

Room as seen by a person with right    hemianopia.

Visual field testing should be a part of a routine eye examination.  These tests detect blind areas of the visual field.  These tests accurately determine where the blind field is in a hemianopic or quadranopic (1/4 field loss) patient and aid the eye care professional to properly fit the Peli Prisms by addressing the specific areas of visual field loss.  They also show the increase in visual field once the prisms are in place.  The pictures of the visual field are called “Visual Field Plots”.  The white areas are the sighted areas.

Visual field plot of a fully sighted person.

Visual field plot of a right hemianope.

The 57Δ Oblique Peli Lens can be ordered after the 40∆ Horizontal Peli Press-on Prisms have been tried and have proven beneficial.  Clinical trials on this lens have recently ended but the data analysis will not be complete until the end of 2011.  Before we make recommendations regarding this design, more research data  is needed.  This lens is designed to detect objects at mid-line while increasing the visual field by 27º.   It is a state-of-the-art lens, and fitting recommendations will not be available until data analysis is completed. The eye care professional prescribing this lens will need to contact Chadwick Optical for fitting recommendations.


Currently, the compelling reason to prescribe this lens is to meet specific visual field requirements of the DMV in the patient’s home state. Eye care professionals are aware of state driving restrictions and should be able to determine if this lens will help the patient achieve the visual field required for licensure based on the patient’s existing visual field.

















Chadwick Optical, Inc., the manufacturer of this lens does not condone driving for hemianopes with or without any Peli Lens unless specifically approved by the DMV in the patient’s home state.

40Δ Horizontal Peli Lens

57Δ Horizontal Peli Lens

57Δ Oblique Peli Lens

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