Graduate Optics

1
Graduate Optics

• Schematic Eyes

2
Schematic Eyes
Page 2.1

• Simplified paraxial representation of the optics
  of real eyes
• Assume that all ocular surfaces are perfectly
  centered (single optic axis)

3
Centered Optical System
Non-centered Optical System
Optic Axis
4
Schematic Eyes
Page 2.1

• Simplified paraxial representation of the optics
  of real eyes
• Assume that all ocular surfaces are perfectly
  centered (single optic axis)

• To use paraxial optics, rays must be limited to
  the paraxial region
• Standard emmetropic schematic eyes are derived
  from the average constants of large numbers of
  real emmetropic eyes (eye focused at infinity
  with crystalline lens relaxed unaccommodated)
• Simulate ametropia (myopia, hyperopia,
  astigmatism) by varying the constants of standard
  emmetropic schematic eyes
• Define three different schematic eyes, from
  complex to very simple
• Rule of thumb use the simplest schematic eye
  that will adequately represent the task/problem
  being considered

5
Gullstrand 1 Exact Eye
Page 2.2
6
Gullstrand 1 Exact Eye
Most complex. Six refracting surfaces, 4
different indices, separate anterior and
posterior corneal surfaces, separate crystalline
lens cortex and nucleus
Page 2.2
Figure 2.1
7
Exact Eye Thick Lens
1.00
1.336
1.336
8
Exact Eye Equivalent Lens
9
Gullstrand 2 Simplified Schematic Eye
Page 2.3
10
Gullstrand 2 Simplified Schematic Eye
Page 2.3
Three refracting surfaces, 2 different indices,
single corneal surface, single homogeneous
crystalline lens medium
Figure 2.2
11
Gullstrand 2 Simplified Schematic Eye (Thick
lens parameters)
Page 2.2
12
The Reduced Eye
Total ocular power reduced to a single
refracting surface
Page 2.5
Figure 2.3
13
Reduced Eye Simplifications
Page 2.5
Figure 2.3

• Reduced surface represents the balance of power
  between cornea and crystalline lens (which favors
  the cornea).
• Because the reduced surface represents a power
  balance, it sits about 1.67 mm behind the
  (anterior) corneal plane
• Pupil considered to coincide with the reduced
  surface (in reality, it is 2 mm behind the
  reduced surface)

14
Reducing the Simplified Schematic Eye
Page 2.6
SS Eye
Reduced Eye
Figure 2.4
15
Paraxial Optics Reduced Eye
60.0 D
16
Paraxial Optics Reduced Eye
60.0 D
17
Paraxial Optics Reduced Eye
60.0 D
18
Reduced Eye Ray-trace
H
N
19
Reduced Eye Ray-trace
H
N
20
Reduced Eye Point Source at Fe
H
N
21
The Human Eye Axes (and angles) Near Vision
Page 2.7
Figure 2.5
22
The Human Eye Axes  Distance Vision
Page 2.8
Figure 2.6
23
The Human Eye Pupillary Axis
Page 2.9
Figure 2.7