Transcript Slide 1 - Hadley School for the Blind

Lighting for
Children with
Immature
Visual
Systems and
those with
Cortical/
Cerebral
Visual
Impairment
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When it comes to learners who are
very young or who have CVI, and how
they are affected by light, we don’t
know much. But we do know some
things.
We know that some learners who
have CVI or are very young,
• Experience light in ways different
from adults with typical vision
• Experience light in ways different
from learners the same age
• Experience light in ways different
from youth and adults with the same
vision diagnosis
• Sometimes experience light in a
synesthetic way.
• Experience confusion and avoidance
in the presence of blue light
• Experience confusion and avoidance
in the presence of very bright light
What are some of
the ways this is
manifest?
• Child turns away from light
• Child shows signs of stress (squint, yawn,
close eyes, rapid blink, waves arms, cries)
• Child becomes non-responsive
• Child respirations change
• Child returns to his/her normal
responsiveness when the offending light
source is removed
Research has shown:
• Studies that involved children with
cortical dysfunction showed that certain
wavelengths of light relieved problems
of characters that shift or move during
reading activities.
• The same studies showed dysfunction
could be induced by certain
wavelengths of light presented during
reading activities. Can we extrapolate
to learners with CVI?
• Some students, especially those with
CVI often become overwhelmed by
certain colors of light or specific
intensities of light, or combinations
of each. We have observed this when
students turn away from a lighted
task.
• Some students are not as bothered
by the light or its color until they
have to perform a reading task, or
use small muscles in a task. Then,
some become overwhelmed. Why?
We must learn a little about the
physics of light
We can see only 3 colors of light.
But you say you can see more than 3
colors! You can see more than 16 mil.
In Addition, Science and
Observation have shown:
• Blue light makes the visual system work
2,000,000,000,000 (2 trillion) times harder than red
light and billions of times harder than green light.
• Ultraviolet makes it work even harder, processing
billions more waves per second, even though we can’t
see it.
• Learners with CVI most often prefer red and yellow
toys, tools, paper, crayons. Why do you suppose that
is? Are they selecting by instinct?
Does he choose based upon what
makes him comfortable?
In my practice, I have tested:
• Visually impaired learners 12 and younger, most
were found to be very sensitive to blue and
ultraviolet light, some more than others.
• Children with CVI and children with very
immature neurological and visual systems worked
more efficiently for longer under red, yellow, and
sometimes green light. They also preferred
working under red or yellow light, and
maintained their preferences over the period I
worked with them.
Follow up, 10-12 years after testing
has shown:
• All but two of the 94 that preferred to work in
red light, still do.
• Of the twenty three that preferred yellow
light, all still do.
• Of the 10 that preferred green light, 7 now
prefer yellow. The other 3 are migraine
sufferers.
Three primary ways you can help:
• Eliminate blue light from the learning
environment. This means changing the color
of the walls and floors if necessary.
• Add red light to the learning environment.
• Allow the child to show you his/her light
preference through his/her toy choices and
alternatives presented during functional vision
assessment.
Before you add color to the
environment of a learner with CVI or
an immature visual system
• Make sure the learner is rested, well-fed, calm
and ready to learn.
• Ascertain what his/her favorite color is
• Use that color as a guide for what color works
for your learner during educational activities
• Situate your learner in a place where the light
is dimmable.
• Be prepared to switch from overhead light to
flashlight or headlamp.
So let’s say you are a little
child with CVI…
Like Lindabelle Saylor
You are easily overwhelmed by bright
light, and you become downright wild
in the presence of blue light.
• The people who educate you are not aware of
lighting limitations for children with CVI. They
put you here.
Or worse, here:
Can learners like Lindabelle benefit
from sensory stimulation rooms at all?
• Even appropriately lit sensory rooms usually
have too much overall stimulation going on.
Yes, if we focus on one appropriately
colored thing at a time, and rest in
between.
Darn Good Sensory Room
What if you’re a little guy with brain
damage and you have a bedroom like
this,
Some principles to remember are:
• Simplify
• Remove blue
• Use black, grey
and white
• Use yellows,
reds for accent
• One large
geometric
• Provide hideaway place.
Nursery
This is an almost
perfect nursery for
a child with CVI.
Variations
One dominant geometric pattern
Or maybe black with just a little color
Things you can do to eliminate blue
light from the learning environment:
• Replace cool white, full spectrum, daylight
tubes and lights with warm white (2700K)
• Provide children with filters to wear
Provide hats to reduce light in the eyes.
• Provide dim light learning environments.
• Provide tinted windows.
• Limit light experiences to small scale
ones that you can control.
• Provide walls in warm colors.
You want a classroom like this.
Not like this:
It takes time to implement these
changes. So lets get started!
We owe it to our students.
Adryanna
Now I must go to get ready for my real job!
Resources
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