What is CVI?


Visual Fields - What Are They?

The visual field is a term that describes the whole of the visible scene when looking in a single direction, both in the centre and out to the side

We have chosen to describe the visual field with both eyes open, as this is what we deal with day-to-day. The medical and vision professions assess and refer to the visual fields of each eye, because this information is used for diagnosis and follow up of what is not seen if the visual fields are limited. We, on the other hand need to know what is seen with both eyes open, so that we as parents and carers can make best use of this vision when helping those people with CVI.

Lack of visual field, or lack of visual attention, or combination of both, each causes things not to be seen, usually to the side.

Here we describe common patterns of lack of visual field in people with CVI and how to find them

In this section the different types of visual field impairment will be explained, although we may not be able to completely explain all the reasons for areas where there are inconsistent responses. This may be due to varying degrees of visual attention in some parts of the visual field, which was mentioned in the previous section, and will be explained in greater detail later in this section.

The first consideration is whether a visual response was not present because the object was not 'seeable' by the person. The background scene in the direction the person is looking needs to be plain, not cluttered or patterned. The object used to test peripheral vision needs to contrast from this background and not move at a moderate pace, not too fast or too slowly.


  • that the background is plain and free of clutter
  • there is sufficient contrast (if the background needs to be a different colour)
  • the object is not moving too fast
  • the object is not moving too slowly.


Your generous donations will be put to immediate use in supporting our charity...

Donate Here

About Us

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