What is CVI?

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Visual Fields - Where Are They?

Understanding Your Visual Fields
Exercise 1

  • Sit or stand with your arms outstretched
  • Look straight ahead and focus only on something central to your vision
  • Without moving your eyes, start wiggling your fingers
  • Are you aware of the movement in your periphery vision?
  • Very slowly start to bring your arms together, wiggling your fingers (never moving your eyes from the central point of contact)
  • Continue until you are aware of your wiggling fingers and stop moving each hand when you can see them

The position of your hands are marks the extremes edges of your left and right visual fields.

Understanding Your Visual Fields
Exercise 2

  • Stand up, and (holding onto something if necessary), place your feet shoulder distance apart
  • Look straight ahead and focusing on a single central point
  • Slowly move one foot off the ground, keeping your leg straight, in front of you.
  • Keeping your focus only on the same central point, slowly move your foot until you are aware of it entering your visual field.

The position of your elevated foot is the extreme edge of your lower visual field.

Here, below, is the image used in the previous section to demonstrate different visual fields.

By using the same shape to represent a visual field (oval) and creating a simple numbering system (based on a clock face, below) we have a template to record responses in the different areas of the person's visual field.

When moving your foot, if you could see it when a few inches off of the floor, then you would mark it near the number 6 (or near 6 o'clock) on a diagram representing your visual field.

The extremes of your left and right visual field, from the first exercise would be around 9 o'clock (left hand) and 3 o'clock (right hand), in someone who was aware of their wiggling fingers with their arms fully outstretched.

Now move both of your outstretched arms up and down, like a snow-angel (whilst wiggling your fingers), to consider your visual fields above and below the 9 o'clock and 3 o'clock marks.

Note the wings of the snow angel - their edges mark the outside edges of your left and right peripheral vision.Note the wings of the snow angel - their edges mark the outside edges of your left and right peripheral vision.

No one has a perfect oval as their visual field, this is just a template used to mark areas where useable (functional) vision is present, not present, or sometimes present.

This picture is an example of binocular vision

It is possible to have full periphery vision, but areas within the centre of the visual fields where responses are either absent, or inconsistent.

All areas of the visual field need to be assessed and understood for this reason.

Try these exercises with some other people, you may find that everyone is slightly different.

This is useful, not to scientifically measure your visual fields (there are visual field tests your optician can perform if you need this). This is useful to give you a sense of your own visual field, and maybe that everyone's vision is slightly different

With CVI these differences in the visual field can have a considerable impact on everyday activities.

We will be using the diagram based on a clock (above) to record the person's visual responses in all areas of their visual field, in relation to both:

  • Vision with movement
  • Vision without movement

We will use a very simple method of recording responses:

  • Colour the section RED if there are never visual responses in this area
  • Colour the section ORANGE if there are sometimes, even if only occasionally, visual responses
  • Colour the section GREEN if there are always visual responses

Use two templates (which you can print from this section) to record your findings

one for moving targets
one for non-moving targets.

You need to complete every segment, separately, in relation to visual responses with movement, and without movement.

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At CVI Scotland we are devoted to helping people understand cerebral visual impairments, and together working towards developing the understanding of this complex condition.