The Glenn A. Fry Lecture

Treating with Spectacle Lenses:A Novel Idea!?

"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

Eli Peli, MSc, OD, FAAO

The Schepens Eye Research Institute Harvard Medical School

My First Refraction

• At the Haifa Zoo (1975)

– Helping Jake Sivak

• The Mongoose refused to be fitted with any type of spectaclesfor day or night use

My Second Refraction Customer

• Helping Mogi Gur and Jake Sivak

• Determine refraction by listening to sounds of neural activity in the cortex, monitored with intracellular electrodes, while changing lenses 13

lever and eye occluder signal

neuronal discharge

Eye

pos

ition

spike timing, AP waveforms, eye position

Cur

sor

mov

ing

with

eye

spik

e tim

ing,

eye

pos

ition

Water pump control

Stimuli generation

Wat

er p

ipe

and

spoo

n

12

5

9

14

15

6

3

7

10

16

17

8

4

12

11

There must be easier ways to refract!

Are there more ways to use thespectacle lenses?

Yes. With Multiplexing!

Multiplexing for Low Vision• Providing 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 lowerfields by about 20 degHigh power prisms (40)

• All positions of gaze affected

• Biocular multiplexing

• Prismatic color fringes mark eye of origin

• Spectral Multiplexing

Left Hemianopia

Instantaneous View with Left Hemianopia

Field expansion for homonymous hemianopia by optically induced peripheral exotropia. Opt. & Vis.Sci 77;453-464

View withthe Peripheral Prisms

Effect Demonstrated with Perimetry

B

WithoutPrisms

Perimetrywith Peripheral Prisms

B

WithoutPrisms

WithPrisms

Cosmetically Acceptable Dangerous?

MultiOptical, Sweden

Peripheral Prisms Spectacles

Peripheral Prisms SpectaclesNew 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

• Block peripheral view

• Top strip for solar glare• Left strip for headlight glare

• Fine adjustments with head position are simple, accurate, and intuitive

Lens Tint

Clip-On

Patent Search

US 5,428,409

US 4,338,003

US 5,252,997

US 4,828,380

US 3,199,296

All for Night Glare All static - no movement

Traffic Lights at Night

Difficult for drivers with color deficiencywith low visionor both

Unilight® LED traffic lights

As seen in Fort Hood, TX & Cheyenne, WY

As seen in Scottsdale AZ

No position clue

No shape clue

Multiplexing Spectaclesfor Red-Green Color Deficiency

• When traffic-light is noted,slight head tilt brings itinto 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 togain high resolution

• Limitations– Ring scotoma, Cosmesis, Social eye contact

45 degree field

In-the-Lens Telescope

View from above

t

Lens thickness, t, limits width of field

Galilean Telescope

Completely embedded in the lens

t

Mirrors Only Design

Looking Through the Carrier

Looking Through the Telescope

Wider Field-of-View

In-the Lens Keplerian Telescope

t

t

Front View Side View

Lens thickness, t, limits height of field

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

Solar Glare

Adaptation withPeripheral Prisms

After few weeks of adaptationPresumed

QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

In-the-Lens Galilean Telescope

Multiplexing Glare Control Lenses

• Block peripheral view

• Top stripe for solar glare• Left stripe for headlight glare

• Fine adjustments with head position are simple, intuitive, and accurate

Disclosure

• I have financial interest in a number of the devices I’ll be talking about.

• I am a consultant to some of the companies

• I have patent applications pending regarding some of the others