3-4 Monochromatic Aberrations Flashcards
Defocus, astigmatism, coma, trefoil, and spherical aberrations are examples of what?
Monochromatic aberrations
Longitudinal and transverse aberrations are of what category?
Chromatic Aberrations
The significance of chromatic defocus depends on _______
Luminance
When the peak of luminance spectru, is in focus, most of the light is less than ___D out of focus.
So when images are superimposed on retina, visibility of target dominated by _______ that are slightly defocused
0.25D
Wavelengths
How many diopters for Longitudinal (LCA)??
2.1D
What’s the average D value for transverse (TCA)?
Is this same if each person measured individually?
0
NO! Will vary greatly but all of them average to 0
Lower wavelength makes the eye more _____. Higher wavelength makes the eye more_____
Myopic
Hyperopic
The chromatic difference of focus (CDF) reduces retinal image contrast by __D of defocus
0.2D
Magnification (CDM) is equal to the axial distance (z) from _____ to ____ point
Pupil; nodal point
Can a CDM less than 1% produce dramatic effects on depth perception?
YES
The chromatic difference of position is directly proportional to :
_____________ (peripheral vision)
__________ (foveal vision)
Stimulus eccentricity
Lateral displacement
A decentered pupil causes tons of ____ when using pinhole
TCA
Transverse chromatic aberration
If you shift your pupil 1mm…you are displaced by ____ degrees or ___ degrees of eccentricity.
Do they both generate the same amount of TCA?
0.12 deg
15 degrees!
Yessssiiirrrr
Transverse chromatic aberration increases _______ with eccentricity
Linearly
A point object emitting two wavelengths of light will produce a double retinal image which gives rise to perception of a double object, the condition is _____??
Chromatic diplopia
What’s an illusion in which differently colored object located at the same viewing distance appear to lie at different distances?
It’s and effect of ____ combined with binocular vision
Chromosteropsis
TCA
BLUE written in red ink on a blue background
___ color has an apparent location at a SHORTER distance than the color ___. Which is apparently FURTHER away
RED CLOSER
BLUE FAR AWAY!!!!
What order aberrations do optometrists fix? What % of all aberrations are this order?
LOWER (defocus and astigmatism)
90%
Correcting monochromatic and chromatic aberrations, this provides a ______ improvement in constraint sensitivity
LARGE
When only monochromatic aberrations are corrected, contrast sensitivity increased by a factor of____
2!!!!!
When only monochromatic & chromatic aberrations are corrected, the contrast sensitivity of the eye is improved by a factor
of ____to _
3.2 to 5
Chromatic difference of position induces___ which affects image contrast
Phase shifts
LCA of they eye doesn’t change; T/F
TRUE
Dispersion of water varies about ___% across
1
Expand the abbreviations
CD-R CDF CDP CDM LCA TCA
..
