Failure of blue-tinted lenses to change reading scores of dyslexic individuals.
BACKGROUND
This study was designed to address a perceived major flaw in past studies investigating tinted lenses and dyslexia; i.e., the lack of a direct, scientifically validated means of diagnosing the type and severity of dyslexia.


METHODS
Sixteen 5th and 8th grade students, found to be dyslexic based on testing via the Dyslexia Determination Test (DDT), were randomly divided into two groups of eight. One group was tested first with blue filters (then, 2 to 5 weeks later, no filters) using the Gates MacGinitie Reading Test for reading comprehension. The other group of eight was tested in the same way, first with no filters, then 2 to 5 weeks later with blue filters. The grade level of the test used for each subject was in accord with the DDT decoding level.


RESULTS
There was no significant difference in reading comprehension level or reading speed when the blue filter condition was compared to the no filter condition.


CONCLUSIONS
Using DDT classification, subjects were found to have mostly dysphoneidetic (mixed pattern) dyslexia. Among this population of dyslexic students, tinted lenses appeared to provide no beneficial effect. We offer an explanation based on neuro-anatomical relationships between the visual system and reading centers in the brain. The hypothesis states that the transient system defect may be an epiphenomenon, which can coincidentally occur in cases of reading disability.
Christenson
G N
GN
Christenson Vision Care, Hudson, Wisconsin 54016, USA.
Griffin
J R
JR
Taylor
M
M
D000293:Adolescent; D002648:Child; D004410:Dyslexia / Q000175:diagnosis / Q000628:therapy*; D005139:Eyeglasses; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D011581:Psychological Tests; D011897:Random Allocation; D011932:Reading; D015351:Vision Screening