1 / 18

SPED 537 ECSE Methods Multiple Disabilities Chapter 4

SPED 537 ECSE Methods Multiple Disabilities Chapter 4. March 13-14, 2006 Deborah Chen, Ph.D. CSU, Northridge. Incidence of Visual Impairments. 1 in 3000 children 46% congenital 38% vision loss in 1 st year of life 25 % totally blind 25 % light perception 50% functional vision.

delu
Download Presentation

SPED 537 ECSE Methods Multiple Disabilities Chapter 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SPED 537 ECSE Methods Multiple DisabilitiesChapter 4 March 13-14, 2006 Deborah Chen, Ph.D. CSU, Northridge

  2. Incidence of Visual Impairments • 1 in 3000 children • 46% congenital • 38% vision loss in 1st year of life • 25 % totally blind • 25 % light perception • 50% functional vision

  3. Definitions • Legally blind • Totally blind • Light perception • Form perception • Partially sighted • Low vision

  4. Types of Visual Impairment • Decreased visual acuity • Field loss • Loss of contrast sensitivity • Color blindness • Ocular-motor problems • Cortical visual impairment • Delayed visual maturation

  5. Causes of Acuity Loss • Retinopathy of Prematurity • Cataracts • Nystagmus • Refractive errors • Strabismus

  6. Refractive Errors • Myopia • Hyperopia • Astigmatism

  7. Strabismus • Esotropia • Exotropia • Hypertropia • Hypotropia

  8. Clinical Vision Tests: Fixationand Eye Alignment • Versions • Hirshberg • Krimsky • Unilateral and alternating cover test • Base-out prism

  9. Clinical Vision Tests • Pupillary response • Vestibular ocular reflex (VOR)- similar to Optokinetic Nystagmus (OKN) test • Refractive Error

  10. Behavioral Tests • Contrast sensitivity • Color vision • Depth perception • Visual fields • Visual acuity (Teller Cards)

  11. Electrophysiological Tests • Visual Evoked Potential (VEP) or Visual Evoked Response (VER) • Electroretinography (ERG)

  12. Checking for Ocular Health Examines the front and back structures, retinal, optic nerve

  13. Ocular Visual Impairment • Atypical eye exam • Consistent visual attention • Nystagmus • Restrictions of visual fields • Occasional photophobia • Eye pressing • Occasional head shaking • Light gazing

  14. Cortical Visual Impairment • Normal eye exam • Variable vision • Short visual attention • No nystagmus • No head shaking • No eye pressing • Light gazing • Photophobia in 1/3 cases ( Dr. J. Jan, Children’s Hospital, Vancouver, B.C. Canada)

  15. Visual Responses Awareness Attention Understanding Fixation Tracking Peripheral Central Simple Complex

  16. Visual Responses Awareness Attention Understanding Large Small Familiar Unfamiliar Near Far

  17. Visual Stimuli • Preferred: • Objects with lights or movement • Geometric designs • High contrast materials • Bright colors • Familiar: • Family members • Clothing, utensils, household items • Toys • Pictures

  18. Visual Saliency • Motivation factors • Lighting (natural, indoor, outdoor, dark) • Position (placement of target) • Distance from child • Highlight or contrast • Illumination of target • Characteristics of target

More Related