Vergences and NPC

Question 1

4 types of testing vergences

Answer 1

Smooth/ramp
Step
Jump
Trombone

Question 2

Why type of vergence testing changes accommodative demand?

Answer 2

Trombone

Question 3

Relative vergence

Answer 3

Change in vergence demand relative to certain distance while accommodative demand is constant

Question 4

Where do relative vergence numbers come from?

Answer 4

Directly off the machine

Question 5

Blur

Answer 5

Pt has used all of fusional vergence ability and must use accommodative vergence to keep target single

Question 6

Break

Answer 6

Point where patient is all out of fusional and accommodative vergence and target is no longer single

Question 7

Recovery

Answer 7

Restoration of fusion

Question 8

Positive

Answer 8

Convergence or added BO demand

Question 9

Negative

Answer 9

Divergence of added BI demand

Question 10

Fusional vergences

Answer 10

Patient’s total fusional ability measured from phoria position

Question 11

What happens to PFv and NFV with an eso deviation?

Answer 11

PFV decreased and NFV increased

Question 12

What happens to PFV and NFV for an exo deviation?

Answer 12

PFV decreased and NFV increased

Question 13

Why is there no BI to blur norm at distance?

Answer 13

Patient should already have accommodation relaxed

Question 14

Why is no blur noted for vertical vergences?

Answer 14

Accommodation does not play a role

Question 15

What prism direction is a supravergence?

Answer 15

Base down

Question 16

What prism irection is an infravergence?

Answer 16

Base up

Question 17

What is the near point of convergence?

Answer 17

Total convergence ability

Question 18

Vergence facility

Answer 18

Measures flexibility of vergence system with stable accommodative demand