Other Hemianopic products

Hemi Reading Glasses

Stock powers are +200, +250 and +300. 10Δ yoked prisms are incorporated for either right or left hemianopia.  Special frame choice eliminates thickness magnification which causes blur and double vision. Also available in custom prescriptions.

Hemi Reader Clip-ons

10Δ yoked prisms shift print away from the blind side into the seeing side for ease of reading.  Available for both right or left  hemianopia. Other prism powers available on request.

Button Press-on Prisms

Placed temporally, monocularly and base out on the side of the hemianopia.  A great way to fit for the VFAS or InWave™ systems without spending  time cutting and shaping press-ons. 

Chadwick’s professional looking die-cut prisms are available in sizes 16mm (5/8) or 19mm (3/4) and in prism powers of 10Δ, 15Δ, 20Δ, 25Δ, 30Δ, and 40Δ

Sector Prisms

Sector Prism  (Rigid Fresnel Embedded Construction)

 

Variations in Sector Prism designs may also be produced using advanced technology of the Peli Lens™ with more cosmetically acceptable results.

15Δ Yoked Base Right Sector Prisms

 Front and top views

15Δ Base Out Bi-temporal Sector Prisms

Front and top views

Sector Prism Clip-on  - 15 Δ prisms 

Determine if patient finds field enhancement prisms beneficial (temporal placement)

Other prism powers available on request.

Placed temporally, monocularly and base out on the side of the hemianopia.  Used to determine if patient is a candidate to have sector style press-ons affixed to glasses. Patients are then taught to scan into the prism.

Button Prisms are also known as the VFAS (Visual Field Awareness System) or the Gottlieb lens.

 

 The round prism reduces the thickness and weight when used in larger frames.  A carrier lens is core drilled and the prism bonded in place.

 

Prism in photo is  20Δ.

Button Prisms

Button or Sector...Which is the better choice?

 

Mechanically they work the same, given the same prism power and the button is aligned properly.  Button prisms are about 19mm or 3/4 inch.  If the prism placement allows 3-4mm clearance in all directions (top, bottom and side) from the edge of the frame, then the round prism is a better choice to reduce weight and thickness. If this clearance cannot be achieved, then the sector would need to be used.  A large variety of prism amounts can be produced in either style.

Custom Optics for Field Enhancement

OD base Rx is +1.50 –2.50 with 7Δ Base Up with laminated 20Δ Nasal and Temporal prisms.  The power was ground on the front to allow the prism to be easily laminated to the spherical surface on the back.

The OS lens was a Mins occlusion lens.  This unique Rx was prescribed for a patient who had suffered a bilateral stroke of the optic nerve; the reason for the nasal and temporal prisms.  A 3rd nerve paresis limited the patient’s upward gaze, requiring the 7Δ base up prism.  In addition, this patient suffered from constant horizontal diplopia requiring occlusion of the non dominant eye.

Chadwick Optical Inc.

Sector prisms were previously known as InWave™ lenses.  Some professionals refer to the sector prism as a “Chadwick lens”, Chadwick Optical in no manner endorses this lens. They are constructed as a verticle Franklin with two lenses bonded together at a seam.