Ocular
Problems
Several reliable studies (Helveston
1969; Blika 1982; Keys 1982; Hiatt 1984) have found
that dyslexic individuals have no greater incidence
of eye problems than do individuals with normal reading
ability. Such parameters as visual acuity, stereo acuity,
ocular alignment and motility, fusion status (break
point amplitude), and refractive error have not been
shown to be significantly different in poor versus normal
readers. Individuals with reading problems should, however,have
a careful eye examination as part of an overall medical
examination. There is no scientific evidence that visual
training (including eye muscle exercises, ocular tracking
or pursuit exercises,or glasses with bifocals or prisms)
leads to significant improvement in the performance
of dyslexic individuals.
A dyslexic
should have his eyes checked, but improved vision doesn't
help that much in learning to read.
Language Problems
According
to Mattis (1978), the primary contributing factor to
dyslexia is an auditory language deficit. Approximately
86% of the individuals identified as dyslexic evidence
an auditory language disorder that prevents the individual
from linking the spoken form of a word with its written
equivalent. In light of this, any individual with reading
problems should have a careful evaluation of his or
her language capabilities and where indicated, appropriate
speech and language intervention should be provided.
This means hearing and
speaking are related to reading.
Visuo-Spatial-Motor Problems
In contrast to language
problems, visuo-spatial-motor factors of dyslexia appear
less frequently (Robinson and Schwartz 1973). Approximately
5% of the individuals identified as dyslexic have a
visuo-spatial-motor problem that interferes with sequential
organization, scanning, and the perception of temporal
and spatial cues. Although visuo-spatial-motor confusion
is common in young children who are just learning to
read, these problems do not tend to account for severe
and persistent reading difficulties unless the child
has missed so much basic reading instruction that he
cannot get caught up. Assessment of visual, spatial,
and motor capacities should be included in the diagnosis
of any coordination or orientation disorder; however,
there is no scientific evidence that interventions such
as neurological and sensory organizational training,
laterality training, dominance training, balance beam,
or reflex inhibition will significantly accelerate reading
performance.
Some
dyslexics have problems visualizing things, problems
with hand-eye coordination, muscle control, sense of
time and space. This should be assessed but treatment
of any of these problems won't be of much help.
Other Factors
The importance
of general intelligence in learning to read has been
examined and shown to be a critical factor in both reading
and language abilities. Investigations of the role of
dominance in handedness, eyedness, and mixed laterality
have produced no consistent conclusions. Studies investigating
low birth weight, EEG abnormalities, temperamental attributes,
attention deficit disorders, birth order, food additives,
and chemical allergies have yielded mixed results. What
is clear is that a wide range of factors can be associated
with reading difficulties but that these factors work
differently in different children.
This means
that the experts don't really know or agree about what
causes dyslexia or how to treat it.
Reference: AVKO Spelling &
Dyslexia Research Foundation |