In this section
There can be changes to the way a person sees after a brain injury has occurred. This can include
problems with the field of vision, the position of their eye and
how the eye moves. There are different treatments and strategies to
help reduce or adapt to vision related difficulties.
The visual system is large
and complex. The picture travels from the eyeball to the
occipital cortex at the back of the brain (see Figure 1).
Information is received by the eyeball and then transferred in
special nerves to the back of the brain where it is decoded into what we
'see'. The occipital lobe is the area of the brain
where information processed by the eyes is decoded and information
about what we see (colour, shape and distance) is
Injury to any part of this
pathway can lead to problems with eyes and vision (See Figure 2).
Problems with eye positions (squint or strabismus, double vision),
eye movements (jerky eyes, nystagmus, poor tracking), visual field
defects and vision problems are common after a brain injury. Over
time these visual difficulties tend to improve.
Double vision (diplopia) is
caused by an imbalance of the eye muscle movements. The two images,
one from each eye, are not aligned properly and so the child sees
this as a double image. A child may close or cover one eye to look at something or have difficulty with balance or judging
depth. They may have difficulty reading and copying. The child may
have a squint or turn of one of their eyes.
Visual field defect
(hemianopia) is due to an interruption of the visual pathways in the
brain. The result is a loss of vision in one half of the
visual field in each eye (See Figure 3). A child may not pay
attention to one side, may bump into objects on one side of the
body or only draw on one side of a page.
Poor visual acuity is when
you cannot see clearly. This is tested by using eye charts with
letters or pictures. Special tests are available to test those
children who cannot name pictures or read letters.
Squint (strabismus) is when
the eyes are not in line with each other. Children may tilt or
turn their head to try and line the eyes up because the eyes
cannot correct the position themselves.
If the problem with vision
is because of an eyeball problem, glasses can sometimes
help. However, glasses are not usually helpful after a brain
injury. Ways to compensate for the problem are needed while
the child's eyes and vision recover.
Patching one eye can
relieve double vision. It is important to swap eyes with the
patch so that one eye does not become weak from lack of use.
Patching can also help strengthen the muscles that cause a squint.
To help a squint, the eye with better vision is patched making the
weaker eye work and straighten its position.
If a child has a very
severe vision impairment, Vision Australia should be
involved. They provide a comprehensive service for home and school
to help children with vision difficulties.
Teaching children to look
or scan left and right will help them be aware of people or objects
in their 'blind spot'.
This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.