What is CVI?


Light Gazing

Light gazing is a well-known and well reported behaviour in children with CVI.

The question is why do they do it?

We have received several accounts from parents suggesting two things:

  • 1. Light gazing is not voluntary
  • 2. Light gazing may be uncomfortable

Below are some of the accounts parents shared:

My son will find it hard to move his visual attention from a very strong light source (recently demonstrated when he missed an entire garden fireworks display as he was unable to look away from the sparkler his brother was holding). The stronger the light source the harder it seems it is for him to pull himself away. I discovered this when he was much younger and in sensory rooms with multiple light sources, a bit like a disco! He would often stare at one of them, but I could see by observing his eye movements that he was trying to move his eyes away but couldn't (with little unsuccessful flickers). He wasn't happy, his eyes seemed stuck, almost trance like, and was always relieved when I physically moved him. At home we have no exposed lights.

We were at the eye clinic, which has bright ceiling lights. The appointment entailed a forty five minute wait in a noisy busy waiting area. As the already challenging environment became more challenging with having to wait, my son's visual draw to the bright overhead lights got stronger and stronger. At first I could distract him, with a song, a cuddle, a play or a tickle. As the wait got longer the draw to the overhead lights got stronger - to the point that I was forcibly burying his head close to me, but whenever I released my grip his head would swing back to find the overhead light source. His gaze was trance like but with a flicker. Each time I pulled him away from the light source I could feel his relief, but it was as though there was a force pulling him (I'm not trying to be over dramatic, I'm just explaining how it was). In the end we left before the appointment, it was just too much for my son.

Only last night we visited the Coca Cola truck and all around us were lights, you'll know the ones, the bright flickering toys that people sell and they completely draw her in. She would probably light gaze more if we allowed her to do so.

Might light gazing be involuntary and possibly uncomfortable?Might light gazing be involuntary and possibly uncomfortable?

We asked one of the very experienced VI teachers we work with about their experience and they noted:

Light gazing is most obviously prevalent in quadriplegic wheelchair users. Other mobile children can seek out light sources and bring them very close to their eyes, this is very common even in more cognitively able children. Children also gaze and fixate on things in their environment and seem to find it hard to shift their visual attention elsewhere.

We asked some parents:

What do you do to stop light gazing and to prevent it?

  • I am very conscious of the lighting we use within the home, I always use soft glow bulbs. We have tinted windows in our cars to help avoid the glare from the sun.
  • We use a buggy with a huge sunshade to stop the sun shining directly on my child. A sunshade on the car window helps too and we have an overall awareness of where the sun is so that we can park my child where the sun is not shining on her.
  • The lighting across the whole house has been adjusted to suit my son, there are no 'naked' bulbs, in his bedroom the main light is an 'uplighter' but we only use that occasionally, there is a high covered wall light which emits enough light. For five years we have had cars with darkened windows in the back (and always will) - before we used temporary window shades. When he was a baby I would put the sunshade up in his pram.

Parents of children with CVI explain the measures they take to stop their child staring at the sun.Parents of children with CVI explain the measures they take to stop their child staring at the sun.

These accounts tell us that for these parents, without necessarily understanding why, they have intuitively made accommodations to stop their child light gazing.

The children who light gaze have different CVI profiles, some have both low vision (reduced visual acuity and contrast sensitivity) and elements of dorsal stream dysfunction. Others do not have low vision, but do have elements of dorsal stream dysfunction. All the children we have heard about have simultanagnostic vision.

We think this is very interesting, because one hypothesis might be that light gazing is a form of simultanagnostic vision, to explain:

  • The brightness creates a strong 'pop-out' effect, this is needed for children with simultanagnostic vision, as their reduced visual attention means they are often only able to see one thing at a time. The brightness of the strong light is enough to draw the child's reduced visual attention.
  • Once the child is looking at the bright light, for the same reason the bright light was able to draw their visual attention (it was very strong), the child is unable to now move their visual attention anywhere else. We call this the competing element of simultanagnostic vision - where looking at one thing which might be very important, or very bright, means that nothing else is seen.
  • Competing simultanagnostic vision can make a child appear distracted, a VI teacher recently described a child refusing to look at eye-gaze because they were 'fixed' on a white plug in a black wall - the child of course didn't see the eye-gaze because it didn't exist, their simultanagnostic vision meant they could only see one thing (once the plug was covered their visual attention was 'released' and they found the eye-gaze). In a mainstream classroom this would look like the child is not paying attention or is distracted. This is how we understand the competing element of simultanagnosia, but with light-gazing something new is added - a possible level of discomfort with an inability for the child to move their vision away from a strong light source.

The competing element of simultanagnostic vision features in the medical literature, but connecting it with light gazing is not, so we must be clear that this is just a possible hypothesis that we think warrants further investigation, because it raises some very interesting questions:

  • Is light gazing enough on its own to suggest CVI?
  • We know CVI is a feature of autism in some children, might light gazing be an observation to prompt further assessment for CVI in these children?
  • Does light gazing suggest possible unknown and undiagnosed simultanagnostic vision, and the other elements of dorsal stream dysfunction?
  • Where light-gazing is observed, might it be worth looking at other features commonly associated with dorsal stream dysfunction, like a lower visual field impairment?
  • Is light gazing different for children with CVI due to occipital challenges like reduced visual acuity and contrast sensitivity and children with posterior parietal challenges including simultanagnostic vision, or both? If so how?
  • Does light gazing have a range or spectrum? Maybe at a lower level it can create a useful motivating pop-out effect, but as the light source gets stronger it becomes more compelling to the point where the child is unable to move away, even though it might be painful?

This child (below) is standing for the very first time, aged two. It was thought that the bright light, and probably movement and the gentle vibrating feeling all together created a strong motivating force, enough for the child to try to support their own weight for the first time. The same child will stare at much brighter lights however. So for this child, lights might be seen to have a range, when not too bright they may create a useful pop-out effect to help draw visual attention and motivate, but when too bright they may be too strong to move away from, possibly uncomfortable and painful, but almost certainly meaning that nothing else is visible. This child has simultanagnostic vision.

We asked our professional advisors who suggested:

These observations are important. These cases show that light gazing can't be helped, and may well be uncomfortable for some children.

If light gazing is related to simultanagnostic vision, then it could be a pointer to the possibility of CVI, perhaps with the dorsal stream being affected. But these ideas need to be investigated.

Is Light Gazing harmful?

High light levels, especially direct sunlight, can cause retinal injury, so it is wise to take precautions.


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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.