Vergence Facility Testing EQUIPMENT NEEDED Gulden vergence facility prism (12 base-out/3 base-in combination) Gulden fixation stick (20/30 target) SETUP 1. If the patient wears glasses for close work, these should be used. 2. Hold Gulden fixation stick tongue depressor 40 cm from patient’s face at eye level. PROCEDURE 1. Say the following: “I want you to look at the letter on this stick. When I place this measuring device in front of your eye, you will see double. Try to get the target to be clear and one as soon as possible. Say ‘now’ as soon as it is clear and one.” 2. Begin with either base-out or base-in and count how many cpm the patient can complete in 60 seconds (one cycle equals successful completion of both base-out and base-in). 3. Record the number of cpm. 4. If the patient cannot do either base-in or base-out, record as 0 cpm, fails base-out or base-in. 5. If the patient cannot do both, record as 0 cpm, cannot do base-in or base-out. EXAMPLES 1. The patient can complete 18 flips in 1 minute. This equals 9 cpm. 2. If the patient cannot regain single and clear vision at all, record as 0 cpm, fails both base-in and base-out. 3. If the patient cannot regain single and clear vision with base-in, record as 0 cpm, fails base-in. 4. If the patient cannot regain single and clear vision with base-out, record as 0 cpm, fails base-out. IMPORTANT POINTS 1. Control accommodation by stressing the importance of keeping the target clear. 2. Stress the importance of trying to regain clear and single vision as quickly as possible

1. By Babli Sharma
M.Optom, B.Optom
Vergence Facility Testing

3.  Gulden vergence facility prism (12 base-out/3
base-in combination)
 Gulden fixation stick (20/30 target)

4.  If the patient wears glasses for close work, these
should be used.
 Hold Gulden fixation stick tongue depressor 40 cm
from patient’s face at eye level

5.  Say the following: “I want you to look at the letter on this
stick. When I place this measuring device in front of your
eye, you will see double. Try to get the target to be clear
and one as soon as possible. Say ‘now’ as soon as it is
clear and one.”
 Begin with either base-out or base-in and count how many
cpm the patient can complete in 60 seconds (one cycle
equals successful completion of both base-out and base-
in).
 Record the number of cpm.
 If the patient cannot do either base-in or base-out, record
as 0 cpm, fails base-out or base-in.
 If the patient cannot do both, record as 0 cpm, cannot do
base-in or base-out

6.  The patient can complete 18 flips in 1 minute.
This equals 9 cpm.
 If the patient cannot regain single and clear vision
at all, record as 0 cpm, fails both base-in and
base-out.
 If the patient cannot regain single and clear vision
with base-in, record as 0 cpm, fails base-in.
 If the patient cannot regain single and clear vision
with base-out, record as 0 cpm, fails base-out

7.  Control accommodation by stressing the
importance of keeping the target clear.
 Stress the importance of trying to regain clear and
single vision as quickly as possible.

8. Thank you