Stereo Distortions (F) Flashcards
If an overall magnifier is held over the right eye, what are the lines on the eikonometer target that are magnified/altered?
vertical lines only
If a axis 90 magnifier (3% R X 90) is held over the right eye, what are the lines on the eikonometer target that are magnified/altered?
vertical lines and cross
What are the cyclotorsional eye movements that compensate for inclinations of objects relative to the head?
disjunctive (cyclofusional)
How does the OFPP (ex: back wall of leaf room) appear with base out prism? 1. Why? 2
- concave and distant
2. magnification increases toward prism apex
What is the law that states perceived size varies directly as perceived distance (ex: may be same size on retina but perceived as larger because brain says it is further away)?
Emmert’s Law
If a axis 180 magnifier (3% R X 180) is held over the right eye, what are the lines on the eikonometer target that are magnified/altered?
cross only (direction opposite of axis 90)
How does the OFPP (ex: back wall of leaf room) appear with base in prism? 1. Why? 2
- convex near
2. magnification increases toward prism apex
What are the distortions of images made by prisms?
- asymmetric magnification (base-apical mag): inc toward apex
- curvature of lines perpendicular to base-apex
- rotation of lines parallel to base-apex
- overal magnification
If magnification distorts stereoscopic distance, then perceived size changes in accordance to what?
Emmert’s Law
If a axis 90 magnifier (3% R X 90) is held over the right eye what will the appearance of the back wall of the leaf room be?
right side appears larger and further away than left side
What is the effect of an overall magnifier over one eye on the leaf room? 1. Why? 2
- no distortion
2. vertical disparities somehow negate effects of lateral disparities
What is the induced effect of an overall magnifier? 1. What is it limited to? 2
- vertical disparities cause an overall global size change (like a zoom on camera)
- about 4% with larger disparities having an incomplete induced effect
What are the type of magnifiers available to use in the eikonometer?
- x90
- overall
- x180
- oblique
What are the cyclotorsional eye movements that compensate for tilts of the head or body?
conjugate
What does an excyclofusional movement while looking at an eikonometer with R X 45 and L X 135 glasses provide?
makes vertical lines straight and alters cross lines so that they appear either have the bottom or top coming towards or away from the viewer based upon whether the images became crossed or uncrossed
If a horizontal magnifier is placed in front of one eye, what must the eye with the magnifier in front of it do to compensate? 1. What do these magnifiers distort? 2
- must make beta angles smaller
2. distance and size
If oblique magnification is held over the eyes, what are the lines on the eikonometer target that are magnified/altered?
cross only (direction is opposite leaf room
If a axis 45 magnifier (3% R X 45) is held over the right eye what will the appearance of the back wall of the leaf room be?
top side appears larger and further away than the bottom
What are the apparatuses for the study of stereoscopic perception of space?
- leaf room
- tilting plane
- eikonometer target
What type of cyclotorsional eye movements influence stereoscopic distortions?
disjunctive (cyclofusional)
What is a device used to quantify stereoscopic spatial distortions? 1. What are the instructions for its use? 2
- The tilting plane apparatus
2. subject rotates target plane to appear fronto-parallel
Does the eikonometer produce an induced effect?
no
If a axis 180 magnifier (3% R X 180) is held over the right eye what will the appearance of the back wall of the leaf room be?
left side appears larger and further away than right side
How are vertical contours altered with prism?
bowed with middle towards base
What is the effect of an oblique magnifier on a vertical line?
lines rotated toward magnification meridian
What magnification effects can the leaf room be good for displaying?
- horizontal
- overall
- vertical
- oblique
- prism
If a axis 135 magnifier (3% R X 135) is held over the right eye what will the appearance of the back wall of the leaf room be?
bottom side appears larger and further away than the top
