1. Binocular balancing ensures equal accommodation relaxation in both eyes during subjective refraction. It does not aim to equalize visual acuity between eyes. 2. There are several techniques for binocular balancing, including successive alternate occlusion, vertical prism dissociation, fogging/Humphiss test, polarized filters, and the septum technique. These techniques add plus lenses until the patient reports equal blurriness between eyes. 3. The vertical prism dissociation technique uses prisms to displace one eye's image vertically while fogging is used, and plus lenses are added until equal blur is reported. The polarized technique uses polarizing filters to partially separate the images while the sept

1. BinocularBalancing
Sahira tayyab
Bsvs
3rd year

2. Binocular balancing
 The final important step of subjective refraction is to make
certain that accomadation has been relaxed equally in the 2 eyes
is known as binocular balancing.
PURPOSE :
– To Equalize accommodation between the two eyes
– Not to equalize the best corrected visual acuity between the two
eyes:
CANNOT BE PERFORMED WHEN:
– px suppresses one eye
– strabismus exists
– px has only one eye

3. Why?
– Pre-presbyopic patients can accommodate during the
distance monocular refraction
– Patients may actually accommodate different amounts in
the left and right eyes

4. Methods for binocular balance
technique:
There are various methods that may be employed to perform binocular balancing of a
prescription . These include:
– 1 Successive Alternate Occlusion
– 2Vertical Prism Dissociation
– 3Blurring or fogging (Humphriss Immediate Contrast)
– 4 Polarized or Vectographic
– 5 Turville Infinity Balance (Septum technique)

5. 1.Successive Alternate
Occlusion:
–Procedure:
– ADD plus lenses binocularly till px barely sees 20 /50 line(6/18) over the
Rx you just achieved from the monocular subjective refraction
– examiner performs slow alternate occlusion
– Px compares of letters between 2 eyes
– “I know this is blurry, I want you to tell me which image is clearer, or are
they both equally blurred.”
– END POINT
– end point is equal acuity b/w 2 eyes
– If one eye clearer than
– Plus lenses added in + 0.25DS steps before clearer eye to equalize the blur

6. 2.Vertical Prism Dissociation:
– Procedure:
– The two eyes will be dissociated by using the prisms in the technique
– Same amount of fog as last technique +1.00
– Same isolated line used 20/50
– Keep the prisms of 3 or 4 Δ BD in OD and 3 or 4 Δ BU in OS
– Equal and opposite
– BD prism will cause image to be higher (top)
– The image will be displaced towards the apex (point) of the prism Δ
– BU prism will cause image to be lower (bottom)
– BD for OD and BU for OS, therefore;
– EGNU5 seen by OD
– EGNU5 seen by OS

7. Cont’d…!!!
–Patient instructions: “I know these images are blurred, I want
you to take a few seconds and look at the image on the top, and then
take a few seconds and look at the image on the bottom, tell me is one
image clearer or are they equally blurred?”
– If the patient reports the top image clearer, add +0.25DS to the OD
and repeat the question
– If the patient reports the lower image clearer add +0.25DS to the OS
and repeat the question
– Now px report both eyes see blur it means we balance the
accommodation with +0.25DS
– At the end remove prism and fog lenses that are use for the balancing
and correct the lenses

8. 3.Fogging method / humphriss immediate
contrast test:
Procedure:
Place +0.75DS/+1.00DS fogging lens before the LE
Fogging verified lens should blur 3_4 lines on chart
Present +0.25DS lens ( lens 1)over RE , replace with _0.25DS lens (lens2)and once again
revert to +0.25DS (lens1)
Px asked to compare lenses 1 2 and 1
Px must report which lens makes target clearer sharper and comfortable to look
If px reports lens 2 better then add _0.25DS lens
Present lenses 1 2 and 1 again
END POINT:
Px reports view through both lenses is the same
Reversal
Once RE Rx balanced fog RE and perform procedure on LE

9. 4.Polaroid Technique
/(Vectographic)
– Polaroid Filters are used to partially dissociate the two eyes
– FZBD FZBD
– While wearing polaroid filters (P in phoropter knob), each
eye sees a separate line and the rod in the middle serves as
a fusion lock

10. Polaroid Technique
– Fog by +1.00 OD and OS
– Same technique as the vertical prism dissociation
– Make appropriate adjustments
– Most natural binocular balance technique as diplopia and
prism are not introduced

11. 5.Septum Technique:
– Separate the visual fields with a septum in the refracting
lane
– Each eye sees part of the line
– Fog by a +1.00 DS
– Same instruction set as vertical prism dissociation

12. Reference :
– American academy
– Zadnik
– Internet
– Notes