A patient with right yoked prisms will have an expansion of visual space where?
On the left
For what two conditions would you NOT recommend an add?
AE, CI (accommodation excess, convergence insufficiency)
In divergence excess, what lenses might you consider adding?
Minus for distance
What lenses would you prescribe in a case of divergence insufficiency?
the Most Plus Best Visual Acuity
As a general rule, how do you orient prism for patients with midline shifts?
Base opposite of the shift
Vision is made up of what?
Higher association areas
What prism orientation would you give to a patient with an anterior midline shift?
Prism adaptation can modulate lateral shift of attention, and what else?
Prompt shifts from one level of processing to another
Over what percent of school age children have a vision problem that could affect the learning process?
What are the possible diagnoses of someone with a normal AC/A ratio?
Vergence dysfunction Basic phoria (Eso or exo)
BI prisms do what to the muscle tone of the neck and upper back?
Reduce muscle tone
The "identification" circle from Skeffington is associated with which system?
Parvo - "what"
What is another name for monocular fixation in a binocular field?
What are the possible diagnoses of someone with a high AC/A ratio?
Divergence Excess (the excesses)
Which is the receptor organ?
What is Prentice position of a prism?
Prism is oriented so that light enters at an angle of 90 degrees to the first surface
BU prisms create an artificial what?
Decrease in the visual spatial volume
What are normal near BO ranges?
What is often the quickest, best option for AI?
The dysfunctions of the visual system are the response to what?
Where does the deviation take place in a prism in Prentice position?
At the exit surface
In convergence excess, it is very important to fix which refractive error?
In convergence excess, prescribing lenses to fix myopia may cause what?
The symptoms to worsen by increasing convergence, and increasing the eso
Prisms affect which 4 systems?
What is the sequence of visual therapy?
Monocular fixation in a binocular field
Which of the Skeffington circles comes first, centering or identification? Why?
Centering. It is the "where". You have to know where something is before you can find out what it is
What are the prerequisites to fusion?
No peripheral suppression
No significant amblyopia
BO prisms displace the visual where?
What are the two main information pathways?
What are the main methods for VT?
Lenses Prisms Motor therapy
Which system is the ambient system?
What prism orientation would you give a patient with a right midline shift?
What are normal distance BO ranges?
If MEM shows ___ or near phoria is ___, what lenses should be given?
BI prisms to what to the visual space?
Create an apparent increase of the visual space
Why is it easier to read for pleasure than to study?
The parasympathetic system kicks in and actually creates an easier environment
When would you not consider minus lenses?
Low AC/A Low CA/C Esophoria Low BI at near Low amplitude of accommodation Fails (-) on accommodative facility testing Is over 9
BO prisms do what to the visual space?
Create an apparent decrease of apparent visual space
When using red/green filters for antisuppression, when will the red be visible?
When looking at a light source or an overlay
BD prisms create an artificial what?
Increase in visual spatial volume
BO prisms do what to muscle tone of the neck and upper back?
Increase muscle tone
What are the 8 conditions under which you would consider prescribing added plus?
High AC/A ratio Hyperopia Esophoria at near Low PRA Normal to high BO at near High MEM Low amplitude of accommodation Fails (-) on accommodative facility
Roughly what percentage of the retinal fibers run in the parvo system?
How are plastic prisms calibrated?
To angle of minimum deviation
What does the sympathetic nervous system do in the eyes?
Relaxes accommodation Relaxes convergence (or stimulates divergence) Prepares the body for danger from a distance
What 4 things can lenses affect?
Perception Posture Orientation Localization
What are the four categories of response?
Catatoxic Syntoxic Run Frozen
BI prism displaces the visual where?
Where will the posture of a patient with a midline shift lean?
Toward the midline shift
What are the higher cortical functions of visual information processing?
Perception Cognition Visual-motor integration Visual-auditory integration Visual-verbal integration Visual integration with other attentional systems
How clear we can see is called ___.
Which lenses enhance figure?
What develops automaticity?
Which lenses enhance ground?
What is the main function of the LGN?
To filter or suppress the information from the eye to the visual cortex
In convergence insufficiency, it is possible that correcting hyperopia will do what?
Exacerbate the symptoms by increasing the exo at near (plus lenses diverge)
When would you not consider added plus?
Low AC/A ratio Myopia Exo at near Low NRA Low BO at near Low MEM Normal amplitude of accommodation Fails (+) on accommodative facility
What are the possible diagnoses of someone with a low AC/A ratio?
Convergence Insufficiency Divergence Insufficiency (The vergence insufficiencies)
BD prism shift spatial volume where?
Up and out from the center of gravity
What are Skeffington's four circles?
Antigravity Centering Identification Speech and language
What are the apparent volume changes in a prism?
Expansion toward apex Contraction toward base
When would you consider adding minus?
High AC/A High CA/C Exo Normal to high BI at near Normal amplitude of accommodation Fails (+) on accommodative facility Is younger than 6
Which system is the focal system?
What does the parasympathetic system to in the eyes?
Miosis Accommodation Convergence
How are glass prisms calibrated?
By Prentice's rule
Which route does the magno pathway follow?
BU prisms shift spatial volume where?
Down and in from the center of gravity
Which is a faster system, parvo or magno?
Which of the VT plans has 4 phases rather than 3?
Which is a faster system and why; vergence or accommodation?
Vergence - it is striated muscle, which is faster than the smooth muscle that controls accommodation
What do BO prisms enhance?
Figure (force convergence)
The parvo system follows which route?
For what two conditions would you give an add?
AI, CE (accommodation insufficiency, convergence excess)
When using red/green filters for antisuppression, when will the red not be visible?
When using red printed material
Which of the responses if the flight response?
What are normal near BI ranges?
What do BI prisms enhance?
Ground (they force you to diverge, taking focus off of what if directly in front of you)
In convergence insufficiency, which refractive error should you be most inclined to correct?
Myopia - minus lenses might help stimulate convergence
Which of the responses is the fight response?
What parts of they eye feed into the parvo system?
Mainly the central retina and foveal receptors
What does the parvo system respond to?
What are normal distance BI ranges?