BSV BINOCULAR VISION BINOCULAR SINGLE VISION

1. SIVA TEJA CHALLA
BINOCULAR VISION

2.  DEFINITION
 NORMAL BINOCULAR VISION
 DEVELOPMENT OF BINOCULAR VISION
 THEORIES OF BINOCULAR VISION
 MECHANISM OF BINOCULAR VISION
 GRADES OF BINOCULAR VISION
 ABNORMALITIES OF BSV
 INVESTIGATIONS

3. DEFINITION
State of simultaneous vision which is
achieved by coordinated use of both eyes so
that separate and slight dissimar images
arising in each eye appreciated as single
image by process of fusion

4. NORMAL BINOCULAR VISION
 REQUISITES
 ADVANTAGES

5. DEVELOPMENT OF BSV
 BEGINS AT 4 MONTHS OF AGE
 PEAKS 2 YRS
 WELL DEVELOPED 4 YRS
 SLOW DECLINE BY 9 YRS

6. THEORIES OF BINOCULAR
VISION
 Theory of correspondence and disparity
 Neurophsiological theory
 Older theories
Alternation theory
Projection theory
Motor theory
Isomorphism theory

7. MECHANISM OF BINOCULAR
VISION
 Visual axis
 Retinal correspondence
 Egocentric localisation
 Horopter
 Pannums fusional area

8. VISUAL AXIS

9. RETINAL CORRESPONDENCE
 Normal retinal correspondence
 Abnormal retinal correspondence(ARC)
Harmonius arc
Un harmonius arc
HARMONIUS angle of anamoly= angle of
strabismus
UNHARMONIUS angle of anamoly< angle of
strabismus

10. EGOCENTRIC LOCALISATION

11. HOROPTER

12. PANNUMS FUSIONAL AREA

13. GRADES OF BINOCULAR
VISION
 SIMULTANEOUS PERCEPTION
 FUSION
 STEREOPSIS

14. RETINAL RIVALRY

15. ABNORMALITIES IN BSV
 Confusion
 Diplopia
 Supression central vs peripheral
monocular vs alternate
facultative vs obligatory

16. INVESTIGATIONS
 For retinal correspondence
 For supression
1.Red filter test
2.Worth FDT
3.Bagolinis striate glass test
4.After image testing

17. Red glass test

18. WFDT
MONOFIXATION SYNDROME

19. BAGOLINIS GLASS TEST

20. BAGOLINIS GLASS TEST

21. AFTER IMAGE TESTING

22. Stereopsis testing
 Stereo acuity is a quantitative measure of
stereopsis, it represents the smallest horizontal
retinal image disparity that give rise to a
sensation of depth.
 Stereopsis is measured in seconds of arc.
 1degree=60minutes of arc, 1minute=60seconds
of arc.
 Normal stereoacuity= <60seconds of arc.

23.  Tests for stereopsis
Qualitative
Random dot stereograms
Synaptophore
Quantitative
Titmus fly test
TNO test
Lang test

24. MACULAR
EXTRAMACULAR
BEGINS AT 2-3 MONTHS MATURE AT BIRTH
IF DEPRIVED NEVER DEVELOPS WILL NOT DEPRIVE
POOR VN AND NYSTAGMUS --
SEVERES FIXATION ---
ONCE DEVELOPED
REINFORCEMENT REQUIRE TILL 9
YRS AGE
---
OTHERWISE AMBLYOPIA
DEVELOPS
---
CONES AND PARVOCELLULAR
GANGLION CELLS
RODS AND MAGNOCELLULAR
ANGLION CELLS
14’ OF ARC OF STEREOPSIS 200’ ARC OF STEREOPSIS

25. BV MACULAR EXTRAMACULAR
SIMULTANEOUS
PERCEPTION
NONE EXCELLENT
FUSION EXCELLENT LIMITED
STEREOPSIS EXCELLENT LIMITED
SO THERE ARE NO ADAPTATIONS IF MACULAR
BINOCULAR VISION IS IMPAIRED AND
THERE WILL BE LIMITED FUSION AND
STEREOPSIS
IF EXTRAMACULAR BV IS IMPAIRED
SUPPRESSION AND ARC TAKES PLACE

26. SUMMARY
 BSV is not inborn,but develops in the first
decade of life
 Abnormal visual experience results in poor or
no BSV
 Reversible only if intervened in the plastic
period of development
 A good understanding of mechanism of BSV
is fundamental in successive treatment of its
anamolies

27. THANK YOU