Visual Perception

Of visual perception

There 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 poor 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 become difficult to process to the correct conclusion when the initial stimulus is faulty.

Behavior/cognition matters 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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“Is it a vision problem?”

Does this child have a visually-based problem?

Our children present with a vast array of problems affecting their development and academics. Sensory problems, trauma, autism, behavior, ADHD and the list goes on. Our children get assessed by OTs, and PTs, neurologists, neuropsychologists, and pediatricians. But did they have an eye-exam? A complete eye exam? Only 40% of children have had their eyes examined by an eye doctor. (1) That leaves all of those children potentially walking around with vision problems affecting their academic and developmental development. Meanwhile, we attempt to teach them catch a ball or write the alphabet or button a button.

“Does he need an eye exam?”

YES!!! Every child, regardless of academic performance or other diagnosis, needs a complete eye exam with a binocular vision assessment and cycloplegic dilation, even if the child has never complained about their vision.  Many times, when a child is assessed with the Convergence Insufficiency Symptom Survey, they learn that they are not supposed to see “words moving” on the page or see double when they read. They had symptoms and were not even aware. Most children with ocular motor or near vision problems will read letters on a chart without difficulty. 20/20 means only that each eye has good acuity. It does not tell us how well the eyes are working together or how hard the eyes are working to make a 20/20 acuity. Only a complete eye exam with binocular assessment and cycloplegic dilation can give the whole picture.

“Is this is visually-based problem?”

There are many signs a child is having a visual-based problem.

  • Eye rubbing
  • unexplained headaches
  • poor handwriting
  • poor reading skills that do not improve with tutoring
  • head turning or tilting when reading
  • closing one eye while reading
  • poor visual motor integration that does not improve practice
  • poor balance or motion sensitivity
  • Diagnosed ADHD that does not respond to medication
  • unable to catch a ball
  • letter reversals
  • visual perceptual problems
  • spacing and size problems during handwriting tasks
  • fine motor delays
  • poor depth perception

These problems maybe mis-diagnosed as things like dyslexia or ADHD and even be treated as such without success for many years.

“Who do I send them to, to make sure they a complete eye exam?”

A good place to start is College of Optometrists in Visual Development. These doctor specialize in the assessment and treatment of eye movement disorders and near vision focusing problems that could be affecting academic performance. You can your local COVD doctor with the search tool on the site. One might also look for an optometrist that specializes in pediatrics or binocular vision.

When an appointment is made, be specific about symptoms and ask for a “binocular vision assessment”.

Every child

Every child needs a complete eye exam. Parents may have many reasons to not get this dome, but you cannot teach a child read or write, or catch a ball that cannot see.

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1.Children’s Vision Screening and Intervention. (n.d.). Retrieved from https://nationalcenter.preventblindness.org/childrens-vision-screening-and-intervention

Autism and Vision

Autism and Sight

There has been several recently published articles on autism with some dysfunctions being found at a higher rate than in the neuro-typical population. One study, published in January 2017, found consistently that children with autism reacted slower to changes in light (pupillary light reflex). The pupillary light reflex was slower when lighting changed and, in darkness, the pupil measured smaller than controls.(1)

A second study, published in 2018, found a higher rate of accommodative problems (17.4% for ASD, vs 4.9% control) for children diagnosed with autism. While there was no substantial difference in the rate of refractive error, this higher rate of accommodative problems makes a complete eye exam with assessment of near vision acuity more important.(2)

A review of evidence found several contradictory studies concerning the prevalence of eye movement defects associated with autism, though most agree that saccades inaccuracy as well as difficulties in tracking are common in ASD. These movement problems, coupled with other fine and gross motor deficits found in autism suggests a cerebellar problem.(3)

Autism and Vision

Difficulties with the integration of visual information is found in several studies. All of these studies point to a lack of integration between the parvocellular and magnocellular tract and reduced communication between these tracts.(3)

Studies found differences in VEPs (visually evoked potentials) studies in the activity of the magnocellular tract compared to neuro typical children. The difference was, most notably, a slower recovery period for the magnocellular tract and therefore, decreased integration of the information. Functionally, this may help explain the visual spatial problems frequently seen in ASD diagnosed children. (4, 5)

Lateral gazing’ behavior was also found in some children with ASD as they attempted to use peripheral vision to reduced central visual pathway input. (3) This behavior is also suggestive of magnocellular tract deficits.

Integration Deficits

A common thread through many of these studies is a decreased integration of visual information and motor pathways and the cerebellum. (6) This lack of integration could help explain the ocular motor and saccade problems, as well as increased incidence of gait problems and toe walking (7,8) and visual motor integration problems found in children with ASD. A study also showed that people with ASD do not make good use of visual information to correct posture (9). Addressing this lack of integration could be helpful making functional progress with children on the spectrum.

Summary

A complete binocular vision exam with cycloplegic dilation is very important for every child with autism (and neuro typical children too) given the potential for a higher rate of accommodative and ocular motor problems and fine motor, reading and handwriting problems.

Given the evidence of integration problems, activities for children with ASD should be “top down” type activities that require the integration of movement and vision.

Much of this research is very recent and found some changes from previous research. Many of the studies suggested these differences in results were related to redefining autism with the release of DSM-5 eliminating Aspergers and pervasive developmental disorder and grouping these into the current terminology of autism spectrum disorder. The inclusion of these subjects in studies have helped improve the understanding of vision and autism. Many of the studies also sited small samples as potential limitations.

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(1)Anketell, P. M., Saunders, K. J., Gallagher, S. M., Bailey, C., & Little, J. A. (2018, March). Accommodative Function in Individuals with Autism Spectrum Disorder. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/29424829

(2)DiCriscio, A. S., & Troiani, V. (2017, July 25). Pupil adaptation corresponds to quantitative measures of autism traits in children. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/28743966

(3)Bakroon, A., & Lakshminarayanan, V. (2016, July). Visual function in autism spectrum disorders: a critical review. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/27161596

(4)Jackson, B. L., Blackwood, E. M., Blum, J., Carruthers, S. P., Nemorin, S., Pryor, B. A., . . . Crewther, D. P. (2013, June 18). Magno- and Parvocellular Contrast Responses in Varying Degrees of Autistic Trait. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/23824955

(5)Sutherland, A., & Crewther, D. P. (2010, July). Magnocellular visual evoked potential delay with high autism spectrum quotient yields a neural mechanism for altered perception. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/20513659

(6)Miller, M., Chukoskie, L., Zinni, M., Townsend, J., & Trauner, D. (2014, August 01). Dyspraxia, motor function and visual-motor integration in autism. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/24742861

(7)Accardo, P. J., & Barrow, W. (2015, April). Toe walking in autism: further observations. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/24563477

(8)Kindregan, D., Gallagher, L., & Gormley, J. (n.d.). Gait deviations in children with autism spectrum disorders: a review. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/25922766

(9)Morris, S. L., Foster, C. J., Parsons, R., Falkmer, M., Falkmer, T., & Rosalie, S. M. (2015, October 29). Differences in the use of vision and proprioception for postural control in autism spectrum disorder. Retrieved March 05, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/26314635

The Hart Chart

Accommodation

Accommodation is one of the mechanisms that allow us to see up close. Accommodation is the focusing of the lenses in each eye. This action, combined with the convergence, allows for us to see clearly up close. 

Accommodation is the result of the contraction of the ciliary bodies in the eye which allow for the lens to get thicker thereby focusing the image better in the fovea. This action also includes the constriction of the pupil which more precisely focuses the light on fovea making the image sharper. Here is video of this in action

 

“Its blurry up close”

When accommodation does not work, one may see blurry up close, get headaches or rub the eyes due to eye strain. The ciliary muscles attempting to make the image clear, causes this discomfort discomfort. Accommodation can be exercised to strengthen it to improve near vision. This is generally performed in conjunction with convergence exercises to improve near vision  when one treats convergence insufficiency.

The Hart Chart

A simple way to improve convergence is using a Hart chart. With this activity, a grid of letters is placed at distance and one is held by the patient, near. The patient then reads a line close (or letter) then a line at distance. This is done with one eye occluded so the accommodative action is exercised as the eye focuses near then far. In my clinic, this performed while standing on balance board to further challenge the patient. This simple activity is quite effective at strengthening accommodation. A Hart chart can be purchased from Bernell, found on the internet and is included on the Vision Rehabilitation for Pediatrics Course Companion flash drive. Heres a video.

The Hart chart is one way accommodation can be strengthened. In optometric vision therapy, lenses can be used to strengthen accommodation using an activity called Accommodative Rock.

Support your local Optometrist

A complete binocular vision assessment should be conducted before performing these tasks to make sure that are appropriate. Only an ophthalmologist or optometrist can accurately diagnose an accommodative problem.

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About the Author

Learn more about this subject in a live course presented by Robert.  Hosted by Vyne Education. 102-20161108-115428-vyne-magnet

Vision Rehabilitation for Pediatrics Course Companion

Vision Rehabilitation for Pediatrics Course Companion

 

I have created a flash drive of resources to further the experience of my live Vyne Course, Vision Rehabilitation for Pediatrics, Seeing the Whole Picture. It is a collection of  web links and PDFs designed to make implementation of the presented course information easier. Click on the picture to get a better look at what is included.

 

The cost of this add-on is $20 USD and you can click here to order .  I will then send you a 128mg flash drive with the all stuff!!

I have recently updated the references for my presentation.

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.

Learn more

About the Author

Learn more about this subject in a live course presented by Robert.  Hosted by Vyne Education. 102-20161108-115428-vyne-magnet

 

(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

 

 

Common Birth to 3 Vision Conditions

Vision Birth to Three

The visual system at birth has a lot of development to do. The early eye exam (6 months to one year) should find anything that may impede this development.

Common Birth to 3 vision problems

Common Birth to 3 Eye problems Pathology Acuity Prognosis Functional Problems Modification
Coloboma failure of the halves of the eye to join completely inutreo, may affect pupil, retina or lid varies depending of retinal damage stable condition glare problems if pupil is affected and retina is functional, reduced bincular depth percpetion sunglasses, motor practice
Optic Nerve Hypoplasia decreased evelopment of the optic nerve, usually assocaied with midbrain/endocrine problems varies from minimal affect to near blindness, possbile field cut, possble nystagmus stable condition Delayed motor development due to reduced visual input.   Refer to TVI at 3 yrs old. vestibular and motor facilitation tasks.
Retinopathy of Pre-Maturity scarring related to excessive blood vessel growth during prolonged O2 exposure in premature infants varies by amount of scarring stable condition depends on level of scarring, may be no delays related to vision based on acuity
Corticol Visual Impairment lack of vision due to visual pathway damage/failure to develop Usually not 100% blind stable condition near blindness, refer to TVI, use contrasting colors, movment and work peripheral to central to investigate amount of vision. Referal to TVI is important for school readiness.
Accommodative Esotropia medial eye turn due to extreme farsightedness 20/20 with glasses in place, eye turn also corrects with glasses improves, but child will remain in glasses throughout life none with early correction, amblypoia without correction glasses should be comfortable and worn at all times.
Infantile Esotropia medial eye turn not related to generally reduced due to amblyopia, may improve with correction varies, tx by surgery vs VT vs Botox reduced motor development per doctors order concerning patching, facillitate motor improvement
Amblyopia reduced acuity due decreased visual pathway development  due to prolonged suppression or lack of stimulation to visual pathway varies, 20/200 or worse to 20/50 depending on patching complaince and glasses wear compliance. may improve with compliance of tx and glasses wear, binocular vision therapy reduced motor dev., head turns, decrease binocular depth perception. Brain with compensate in time motor dev facilitation, exercise amblyopic eye if currently patching, binocular vision activities
Strabismus eye mis-alignment at rest, corrected with surgery vs VT vs Botox varies, generally reduced due to amblyopia varies greatly. Long term, brain adapts to suppression of the turned eye reduced motor dev, self-esteem, self conscious of turned eye, reduced binocular depth perception eye exercises per doctors order, facilitate motor development

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About the Author

Learn more about this subject in a live course presented by Robert.  Hosted by Vyne Education. 102-20161108-115428-vyne-magnet