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The Glenn A. Fry Lecture
Treating with Spectacle Lenses:
A Novel Idea!?
Eli Peli, MSc, OD, FAAO
The Schepens Eye Research Institute
Harvard Medical School
"What has been is what will be,
and what has been done is what will be done;
there is nothing new under the sun.”
Ecclesiastes 1:9
My First Refraction
• At the Haifa Zoo (1975)
– Helping Jake Sivak
• The Mongoose refused
to be fitted with any
type of spectacles
for day or night use
My Second Refraction Customer
• Helping Mogi Gur and
Jake Sivak
1
2
3
Stimuli generation
Water pump control
spike timing, AP waveforms, eye position
Eye position
6
5
spike timing, eye position
4
Water pipe and spoon
• Determine refraction by
listening to sounds of
neural activity in the
cortex, monitored with
intracellular electrodes,
while changing lenses
7
9
8
17
10
16
11
13
15
12
14
neuronal
discharge
lever and eye occluder signal
There must be easier ways to refract!
Are there more ways to use the
spectacle lenses?
Yes. Multiplexing.
Multiplexing for Low Vision
• Provide peripheral (wide field-of-view)
together with central (high resolution) vision
in ways that make them
perceptually separable and useful
– Many different forms of multiplexing • Spatial (superposition), Temporal (alternating),
Biocular, or Spectral (colors)
– Maintaining free head & eye movements
Peripheral Prisms for Hemianopia
• Expands upper and lower
fields by about 20 deg
High power prisms (40)
• All positions of gaze affected
• Biocular multiplexing
• Prismatic color fringes
mark eye of origin
• Spectral Multiplexing
Left Hemianopia
Instantaneous View
with Hemianopia
Field expansion for homonymous hemianopia by optically
induced peripheral exotropia. Opt. & Vis.Sci 77;453-464
View with
the Peripheral Prisms
Effect Demonstrated with
Perimetry
Without
Prisms
B
Perimetry
with Peripheral Prisms
Without
Prisms
B
With
Prisms
Peripheral Prisms Spectacles
Cosmetically Acceptable
MultiOptical, Sweden
Dangerous?
Peripheral Prisms Spectacles
New more attractive, safer designs
Chadwick Optical
Solar Glare
• Need to block peripheral
field
• Sunglasses and tinted
visors-not dark enough
• Opaque visor-fixed
• Hand position is
adjustable
Headlight Glare at Night
Coming from a limited section of peripheral field
Multiplexing Glare Control Lenses
Lens Tint
• Block peripheral view
• Top strip for solar glare
• Left strip for headlight glare
• Fine adjustments with
head position are
simple, accurate, and intuitive
Clip-On
Patent Search
US 3,199,296
US 4,828,380
US 5,252,997
US 5,428,409
US 4,338,003
All for Night Glare
All static - no movement
Traffic Lights at Night
Difficult for drivers
with color deficiency
with low vision
or both
Unilight® LED traffic lights
As seen in
Fort Hood, TX
& Cheyenne, WY
No shape clue
No position clue
As seen in
Scottsdale AZ
Multiplexing Spectacles
for Red-Green Color Deficiency
• When traffic-light is noted,
slight head tilt brings it
into the red-tined zone
• Red light shines through
• Green light is blocked
Successful application of Temporal Multiplexing
Bioptic Telescope
• Wide field through the
carrier lens
• Occasional head tilt to
gain high resolution
• Limitations
– Ring scotoma, Cosmesis, Social eye contact
45 degree field
In-the-Lens Telescope
Galilean Telescope
View from above
t
Lens thickness, t, limits width of field
Mirrors Only Design
t
Completely embedded in the lens
Looking Through the Carrier
Looking Through the Telescope
In-the Lens Keplerian Telescope
Wider Field-of-View
Lens thickness, t,
limits height of field
t
t
Front View
Side View
SimulVision-Spatial Multiplexing
Conclusion
• Multiplexing offers a new way of thinking
about low vision devices
– Electronics or optics
• Multiplexing is useful in other applications
• Cosmetic considerations are critical to the
success of any spectacle born device
– We are all vain
“…vanity of vanities; all is vanity”
Ecclesiastes 1:2
Thank You!
Supported generously by NIH grants