Page 8 - BOAF Journal 1 2012:2707

Behavioral Optometry
BOAF
Volume1 Number1 2012
This can be achieved by tilting the head down towards the right shoulder to allow „stress free“horizontal align- ment of the eyes. Achieving this sets up major modifications in muscular balance throughout the body :
- This head tilt is provided by contraction of the right, and relaxation of the left, neck muscles.
- This in turn causes con- traction of the left trunk and relaxation of the right trunk, muscles.
- This causes a pelvic tilt, with the left leg ending up “shorter” than the right, lead- ing to variation in the length of stride between the legs.
There will therefore be strain and abnormal wear and tear in the muscles and joints from the feet to the skull , walking "gait" will be altered with a longer stride on the left - causing a repetitive adjustment in at- tempting to walk a straight line, causing damage to spine, spinal discs, hip, knee and ankle, re- duce efficient movement of the neck, and, all because of a
small vertical oculomotor imbal- ance.
The same thing can also occur in reverse. Postural prob- lems can give rise to leg length anomalies leading to pelvic tilt, contraction of trunk muscles of the raised side. Relaxation on the lower side, with respective changes in the neck leading to a head tilt which can cause an apparent vertical oculomotor muscle imbalance leading to asthenopia!
3) The effect of neck problems in Optometry
i) Lens adaptation difficulty.
When the neck is stiff or has a reduced range of comfortable movement in presbyopic pa- tients, they are likely to have adaptation problems to bifocal and varifocal lenses, being un- able to comfortably adjust their chin position in order to look through the correct part of the lens. This is particularly a prob- lem when viewing a VDU screen, which often requires a higher chin position for longer periods of time. Conversely, these lenses may in some cases be beneficial, as they will actu- ally activate exercise and movement of the neck. Patients with reduced functional visual fields will exhibit reduced range of clear near vision, requiring them to lean in close to their VDU screen causing neck, back, shoulder etc discomfort ref
ii) “A” & “V” syndrome af- fecting head posture or de- pression
A number of our patients possess an exophoria, a latent tendency for the eyes to di- verge, which increases when looking up – a “V” exophoria or increases when looking down, an “A” exophoria. Elevation of the head will occur in a “V” exophoria, in order to put the eyes in position of least exo- phoria, and consequential posi- tion of least effort to maintain binocularity. Similarly depres- sion of the head will occur in the case of an “A” exophoria. This however may in itself give dis- comfort in the neck leading to tired muscles and headaches. This may be a particular prob- lem when working for long peri- ods on a computer or similar visual task.
iii) Eye movement problems and head tilts in children with educational difficulties
70% of children with educa- tional difficulties have been quoted as having eye move- ment difficulties 75% of adults with educational difficulties 90% of juvenile delinquents (fol- lowing therapy the re-offend rate dropped from the normal 70 – 30 %!)4
It can be observed when carrying out a motility or pursuit eye tracking test (without head restraint), that these children will prefer to use head, in prefer- ence, to eye movements, and, in some cases, excessive turn- ing of the head so that the eye movements go in the opposite direction to the desired direction - no wonder they have reading difficulties.
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