Texas Education Code (TEC) §38.003 defines dyslexia in the following way:
(1) “Dyslexia” means a disorder of constitutional origin manifested by a difficulty in learning to read, write, or spell, despite conventional instruction, adequate intelligence, and sociocultural opportunity.
(2) “Related disorders” include disorders similar to or related to dyslexia such as developmental auditory imperceptions, dysphasia, specific developmental dyslexia, developmental dysgraphia, and developmental spelling disability.
The International Dyslexia Association defines dyslexia in the following way:
"It is characterized by difficulties with accurate and / or fluent word recognition and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive abilities and the provision of effective classroom instruction. Secondary consequences may include problems in reading comprehension and reduced reading experience that can impede growth of vocabulary and background knowledge."
Adopted by the IDA Board of Directors, Nov. 12, 2002. This Definition is also used by the National Institute of Child Health and Human Development (NICHD).
If you suspect that your child may have dyslexia or other difficulties with learning, talk with your student's teacher.
Other resources that may be helpful can be found below including
2) The Dyslexia Handbook published by the Texas Education Agency.