Visual Perception

Of visual perception

There are many assumptions made about a student’s performance on visual perception tests. After all, these tests give norm’ed results which can be helpful in goal making and identifying a potential cause for an academic problem.

But do the results actually reflect visual perpetual skill?

Many factors can hamper the reliability and validity of visual perceptual testing.

  • Visual acuity-is this patient in best correct visual acuity? Have they had an eye exam and been prescribed the appropriate glasses? Do the glasses fit well to allow for the intended benefit?
  • Binocular vision skills?-Poor binocular vision skills can result in double vision and blurred vision up close which can affect the results of visual perceptual testing?

These two factors, when not corrected, make for a “garbage in-garbage out” situation and taint the results of the testing, increasing the likelihood for invalid results in the patient.

Imagine putting a glove on a patient then asking that patient to identify coins that they are holding in the gloved hand. They would have a difficult time doing this, not because of an inability to process the feel of the coin, but because the stimuli to be interpreted is muted. It becomes difficult to process to the correct conclusion when the initial stimulus is faulty.

Behavior and cognition matter too

With best corrected acuity and good binocular visual skills, other factors, such as attention can play a role in visual perceptual testing. Common visual perceptual tests can take as long at 45 minutes of monotonous testing making even the most attentive children bored and possibly affecting results.

Most visual perceptual tests are designed so the child with a visual perceptual problem misses three consecutive items in a section, then advance forward to the next section. The pattern is irregular (child misses one item then 3 correct then misses two items, then one correct) perhaps attention is playing a role in the test results.

Visual Percetual Testing

In my clinic, I do not test visual perception until after binocular vision issues have been corrected and the patient is in best corrected visual acuity.

With these things in place, you will find visual perception intervention much more effective and testing will be more valid and reliable.

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Learn more about this subject in a live course presented by Robert.  Its now available as a webinar too!! Hosted by PESI Education

 

 

Screen Time for Children

Tablets and iPhones and Kindles..oh my!

This generation of children will not know a world without immediately accessible information. They will not live in a world where information is unable to be accessed. Every question answerable with the right choice of words entered in a search engine. Computers now augment the classroom with lessons and tests being presented digitally where once they were presented by a teacher.

The side effects of technology

As therapists, we recognize that a child sitting in front of a screen for hours is not healthy. But does science support that extended exposure to the devices is harmful?

  • Survey of 900+ children in an advantaged school found children with found girls using devices 219 min/day and boys 207 min/day. These children showed increased incidence of neck/should discomfort and increased visual symptoms. (1)
  • Another study of 502 children showed that the more screens a child had available in their bedroom the more likely the child to be obese and have poor sleep habits and a sedentary life style. (2)

These studies help show that what a child is not doing (movement, etc) while on tablet devices is having a negative impact on their health.

Computers in the Academic Environment

School systems boast of their computer to student ratio equating the use of computers and tablets to a quality education. But extended use of computers cause the same problems they do for adults, and perhaps more as children tend to not to be as self-aware of these problems, show more adaptability and work in environments without optimal lighting (3)

A study of 320 children showed increased incidence of vision problems in children who played video games on computer for over 30 minutes per day. As screen time increased, so too did the visual complaints. Complaints like headaches, dizziness and diplopia and decreased stereopsis (binocular depth perception) we all common among these children. (4)

Extended use of computers and screens lead to problems because of what the child is not doing while on the device and the devices are linked to increased vision and musculoskeletal problems. So what do we do?

Throw Them All Out?

Tablets and computers are part of our culture now with everyone interacting with devices throughout the day. There must be a balance in the use of these devices.

A properly balanced play diet that would include screen time but also include social, active and creative play. An examination of the of the skills learned during screen time would make screen time more valuable while balancing this with active play IRL (“in real life”)

LearningWorksForKids.com offers a great search engine to help identify apps that can be useful for teaching skills to children and help screen time be useful.

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About the Author

Learn more about this subject in a live course presented by Robert.  Its now available as a webinar too!! Hosted by PESI Education

 

(1) Straker, L., Harris, C., Joosten, J., & Howie, E. K. (n.d.). Mobile technology dominates school children’s IT use in an advantaged school community and is associated with musculoskeletal and visual symptoms. Retrieved December 19, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/29103354

(2) Chaput, J. P., Leduc, G., Boyer, C., Bélanger, P., LeBlanc, A. G., Borghese, M. M., & Tremblay, M. S. (2014, July 11). Electronic screens in children’s bedrooms and adiposity, physical activity and sleep: do the number and type of electronic devices matter? Retrieved December 19, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/25166130

(3) Kozeis, N. (2009). Impact of computer use on children’s vision. Retrieved December 19, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2776336/

(4) Rechichi, C., De, G., & Aragona, P. (2017, November 01). Video Game Vision Syndrome: A New Clinical Picture in Children? Retrieved December 19, 2017, from https://www.ncbi.nlm.nih.gov/pubmed/28850642