ped01-1

• Visual acuity


  The ability to distinguish forms or discriminate among details
• Legal blindness


  Having visual acuity of 20/200 or less in the better eye with the use of corrective lens
• Partially sighted


  Individuals whose visual acuity in the better eye after correction falls between 20/70 and 20/200
• Tunnel vision


  A condition of having a perception of viewing a world through a narrow tube
• Learners with difficulty seeing


  • Having impairment in vision that, even with correction, adversely affects a learner's educational performance
  • Includes both partial sight and blindness
• Total blindness


  Receiving no useful information through the sense of vision
• Functional blindness


  Having so little vision that one learns primarily through tactile and auditory senses
• Characteristics of learners with difficulty seeing

  • Cognition and language
  • Motor development and mobility
  • Social adjustment and interaction
• Learners with difficulty seeing usually perform more poorly compared to those with normal vision in terms of cognitive tasks that require comprehension or relating various kinds of information
• Blindness may also result in delays and deficits in motor development
• Children with visual impairment may engage in less play, which could affect their social skills development
• Learners with visual impairment are prone to develop stereotypic behavior such as repetitive body movements
• Amblyopia


  Reduction in or loss of vision in the weaker eye from lack of use
• Astigmatism


  Distorted or blurred vision caused by irregularities in the cornea or other surfaces of the eye that produce images on retina not in equal focus
• Cortical visual impairment (CVI)


  Impaired vision caused by damage to or malfunction of the visual cortex or optic nerve (or both)
• Hyperopia


  Difficulty seeing near objects clearly but able to focus on distant objects
• Myopia (nearsightedness)


  Distant objects are blurred or not seen at all but near objects are seen clearly
• Nystagmus


  Rapid, involuntary, back-and-forth movement of the eyes, which makes it difficult to focus on objects
• Strabismus


  Inability to focus on the same object with both eyes because of an inward or outward deviation of one or both eyes
• Snellen chart


  Used to test visual acuity, consisting of rows of letters with each row corresponding to the distance that a normally sighted person could discriminate letters
• Vision Services Severity Rating Scale (VSSRS)


  Developed to assist the Teacher Consultant for the Visually Impaired (TCVI) or Teacher of the Visually Impaired (TVI) in making recommendations for services to students who are blind or visually impaired
• Conductive hearing impairment involves a problem with the conduction or transmission of sound vibrations to the inner ear
• Sensory hearing impairment refers to the damage to the cochlea
• Neural hearing impairment refers to the abnormality of the auditory nerve pathway
• Mixed hearing impairment refers to any combination of conductive, sensory and neural hearing loss
• Unilateral hearing loss is hearing loss in one ear
• Bilateral hearing loss is hearing loss in both ears
• Congenital hearing loss is hearing loss present at birth
• Acquired hearing loss is hearing loss that develops after birth
• Prelingual hearing loss is hearing loss before the development of spoken language
• Postlingual hearing loss is hearing loss that happened after the development of spoken language
• Otitis media is a temporary, recurrent infection of the middle ear
• Meningitis is a bacterial or viral infection of the central nervous system and is the leading cause of postlingual hearing loss
• Meniere's disease causes sudden and unpredictable attacks of vertigo, fluctuations in hearing, and tinnitus
• Noise exposure can cause repeated exposure to loud sounds leading to hearing loss
• Genetic factors can cause autosomal dominant hearing loss when one parent has the condition
• Deafness


  Severe hearing loss in that the learner is impaired in processing linguistic information through hearing, with or without amplification, and which negatively affects a learner's educational performance
• Hearing loss


  Loss in hearing, whether permanent or fluctuating, that negatively affects a learner's educational performance, other than those that qualify as deafness
• Residual hearing


  Some sounds perceived by most deaf people, but they still use vision as their primary mode of learning and communication
• Hard of hearing


  Individuals who can use their hearing to understand speech, generally with the help of a hearing aid