CVI characteristics

Light: Friend and Enemy

Lightgazing can be such a strong feature for children in the early phases for CVI.

With the skills of children with a greater impact of CVI, we struggle to gain a child’s visual attention to a more meaningful visual targets. We need to control all light sources from overhead and from surrounding doors and windows. We also recognize that placing meaningful visual targets against Lightboxes, iPads and other backlighted surfaces can support that more meaningful gaze to objects. We understand that lighting objects and lighted objects will more easily gain attention, the first skill for visual learning.

As visual attention improves, children can break their attention to light to look at meaningful materials and light remains a valuable tool to gain attention and increase the length of looking. We still need to control overhead and outdoor light sources for the best visual attention.

As visual recognition improves,backlighting helps some children’s understanding of 2D materials: letters, numbers and pictures and reduced their visual fatigue.

All children’s reactions to light are part of any assessment of their CVI.

Visual Neuroscience: Understanding Visual Skills Scaffolding

To understand CVI at its deepest level, it is important to educate ourselves about neuroscience and learning especially as it relates to vision.

This is a fascinating TED Talk by Pawan Sinha, a visual neuroscientist at MIT. Mr. Sinha and his team research how the brain interprets the visual information that our eyes see. This research looks further into the mystery of how the visual system’s skills develop. It shatters long held beliefs about the critical periods for vision development and highlights the building understanding of plasticity.

This knowledge led Mr Sinha to important work restoring sight for children with visual impairments in India. These children undergo surgery to remove cataracts, an ocular visual impairment. Because these children’s brains did not receive visual information prior to surgery, they still struggle to see when the cataract is gone. Sinha and his team were then able to document how their brains learned to interpret visual information over time.

What I find most fascinating is the discovery of motion as the fundamental building block for visual scaffolding. The children are followed weekly after surgery. Perception of motion develops first (week one), then shape recognition with movement (week two), color recognition (week three), face detection (week four) and finally at 40 weeks post surgery, object recognition.

I doubt when Mr. Sinha talks of “face detection” that he means “facial recognition”. In teaching children with CVI, we know this develops much later.

What does this suggest to me?

  • Scientists have so much more to learn.
  • Recovery or development of sight is possible at any age due to plasticity of the brain.
  • Vision develops with understanding of the careful scaffolding of visual skills based in motion.
  • I need to continue to understand the brain and its functioning as it relates to building visual skills.

http://www.ted.com/talks/pawan_sinha_on_how_brains_learn_to_see