7-8 Optical Models Of The Eye

Question 1

Eye models fall into what two categories?

Which is a working device that mimics functional behavior of real eyes? It can have a variety of embodiments: physical, mathematical, or computational.

Which is a mechanistic summary of everything we know about the eye’s optical system and how it works?

Answer 1

The encyclopedia and the toy train.

The toy train

The encyclopedia

Question 2

How are encyclopedias used?

How are working models used?

Answer 2

Scholars use them to store and retrieve knowledge. Compact representation about ocular mechanisms. Too complicated for many details.

Utilitarian tools for problem solving. Real world problems get solved, but may over simplify important features of the eye

Question 3

What Greek man described the eye as 3 concentric spheres containing the various humors required by the visual sense?

Who preserved Greek teachings and also observed the emergence of the optic nerve from crystalline lens, where vision was thought to occur? Was mathematician and astronomer

Answer 3

Democritus

Ibn al-Haytham (Alhazen)

Question 4

In 1543, who launched the renaissance of anatomy to adhere to the teachings of the Roman physician Galen?

Who was considered the inventor of the eyeglasses?

Who was the first to realize the existence of the inverted retinal image? He understood how to correct for refractive errors

Answer 4

Vesalius

Salvino degli Armati

Kepler (1604)

Question 5

Master lens maker Torricelli, believed that the ideal shape for the lens surfaces was ___________. But today we know it’s the opposite.

Answer 5

Spherical

Question 6

A ______ is a diagrammatic presentation, or framework, that organizes our understanding of a complex system.

Thus, the ________ eye is a diagram that summarizes and organizes our understanding of the eye as an optical system. Provides framework for thinking about how retinal image formed

Who had the first functional diagrams that showed refraction of light rays to form image on retina?? He also invented the first device for measuring refractive error, Called the _________

Answer 6

Schema

Schematic

Scheiner . Optometer

Question 7

Who independently re-discovered snell’s law in 1637 to show how spectacles work?

350 years ago, who discovered that white light contains a spectrum of colors?

Who in 1851 introduced average schematic eye and reduced it further into cardinal points??

Answer 7

Descartes

Isaac Newton

Listing

Question 8

In the 20th century, eye models only became better. What are the 5 important developments?

1. Better __________
2. Discrete approximations to continuous ____ profile
3. Changes over the ________ incorporated
4. Development and progression of ________ ________.
5. _______ surfaces account for aberrations, wide FOV, changes due to accommodation

Answer 8

1. Biometrics
2. GRIN
3. Lifespan
4. Refractive error
5. Aspheric

Question 9

What can using model eyes predict? (2 things)

Can also calibrate imaging tools like:

1. ____________
2. ______ camera
3. OCT

Answer 9

Refractive surgery outcomes.
Forward scattering effect (glares and halos)

1. Autorefractors
2. Fundus camera

Question 10

Is an anatomically correct model eye a complete description of the eye’s optical system?

An anatomically correct model is important for many applications, but may be too _____ to be useful in other applications

The law of __________ recommends using the simplest model adequate for an application. This may be a model that’s functionally accurate, but anatomically inaccurate

Answer 10

YESSSS

COMPLEX

Parsimony

Question 11

Scholars use _________ model eye to store and retrieve knowledge

Who was the first to realize the existence of the inverted retinal image, and understand how to corrective lenses worked?

Scheiner invented the first ever optometer to measure the ________ ________ in the human eye

Answer 11

encyclopedia

Kepler

Refractive error

Question 12

What’s an optical model that summarizes our knowledge of the eye as an optical system?

Cardinal points, focal lengths, axial image location and magnification are examples of ___________ __________ optics (paraxial)

Refractive errors, accommodations, optical aberrations can be used to predict what?

Answer 12

Schematic eye

Applied geometric

Predicts impact of optical defects

Question 13

Are models with equal cardinal points functionally equivalent?

Regarding focal points, what’s the axial object position for which the image will be formed at infinity ?

What about the axial image point of an infinitely distant object?

Answer 13

YASSS

1st focus

2nd focus

Question 14

What do principle points do?

Which one is located where the citing rays parallel to the optical axis intersect the refracted rays coming from the 1st focal point?

Which one is located where the incident rays parallel to the optical axis intersect the refracted rays converging to the 2nd focal point?

Answer 14

Locate front and back surfaces of an equivalent thin lens

1st Principle point

2nd PP

Question 15

The cardinal points are _ pairs of points that define an equivalent ____ lens whose paraxial performance is identical to the original thick lens or combination of lenses (eye).

Unlike the ideal thin lens, the _________ thin lens has a front and back surface, what are the two and what do they entail?

Answer 15

3. Thin.

Equivalent.

P=location of FRONT surface

P’= location of BACK surface

Question 16

The equivalent power of the eye is around __D.

Anterior focal length is around __._mm

Posterior focal length is around __._mm

Answer 16

60D

16. 7
17. 2

Question 17

Nodal points have the property that any incident ray which passes through the ______ nodal point leaves the system as though from the ________ nodal point AND parallel to the incident ray (unchanged, but displaced.

Answer 17

1st

2nd