When children have difficulty in school, from learning to read to understanding fractions to seeing the blackboard, many parents and teachers believe that these children have vision problems.

And sometimes, they're right. Glasses or contact lenses will help children see the board better, and they may help children succeed in school if they have difficulty seeing. Ruling out simple refractive errors is the first step, but they're not the cause of all learning problems.

Another reason for school difficulty is a learning disability. Learning disabilities are more than dyslexia, a language-based learning disability that frequently causes children to reverse letters or words. Learning problems affect reading, writing, speech, attention span, comprehension and social interaction, much more than an easily corrected refractive error.

Vision is an important part of learning. Almost 80 percent of what a child learns throughout his educational career comes to him visually. In order for vision to help learning, rather than hinder it, all three parts of visual function must be working properly:

1. State of the eyes, which includes eye health, visual acuity and refractive errors such as nearsightedness, farsightedness and astigmatism;

2. Eye function, which includes focusing, the eyes working as a team rather than independently, and eye movement;

3. Visual perception, which includes understanding what you see, identifying it, judging its importance and linking it to previously stored information, as well as eye-hand coordination. Visual memory is another part of visual perception. This entails recognizing words that you have seen previously, and using the eyes and brain together to form a mental picture of the words you see. For example, when you read the word "cat," you do more than see the letters C-A-T. You also form a picture of a cat in your brain. Or, you laugh out loud after reading a funny passage because you can picture the events happening in your mind.

Many professionals, including teachers, pediatricians and some eye care practitioners, focus only on the first of the three parts of visual function - the state of the eyes, specifically refractive errors. If vision is defined as seeing a certain size letter on a chart at a specific distance, then many children will have perfect vision even if they must wear glasses or contact lenses. On the other hand, if vision is defined as seeing clearly, understanding what you see and processing what you see, some children will be diagnosed with a visual dysfunction that affects how they learn.

It's much more difficult to learn when you can't even see what's on the blackboard.

As an example, a child who has blurred vision won't learn effectively or efficiently because he can't see clearly to write, or read a textbook or what's on the board. Looking at vision in another way, give a child a book written in Greek and test him on the contents. Obviously the child will fail the test. He may see the book clearly but simply not understand the information inside.

Learning disabilities usually occur between the ages of one and seven and can be classified in four behavioral categories: 1) speech and language; 2) nonverbal; 3) attention disorders; and 4) pervasive developmental disorders, also called the autism spectrum.

Speech and Language

This learning disability is categorized in three main divisions: articulation, expressive language and receptive. Those three are then broken down further into a large set of subdivisions.

Articulation disorders can be first seen when your child doesn't speak in a coherent voice flow. This speech problem can usually be traced back to a problem with the larynx (voice box) or nerves in the throat and tongue. This disorder doesn't affect learning as much as the others, and children with articulation disorders should be seen by a speech therapist.

Expressive language dysfunction is caused by a processing breakdown in the brain. Children with this learning disability cannot express their thoughts via speech or the written word. They know what they're talking about, but can't make others understand.

Receptive disorders include dyslexia. This learning difference prevents children from deciphering the phonetic coding of words and connecting them with sounds. Receptive disorders very much affect children's learning by failing in retrieving information. These children hear well and understand what is spoken to them, but cannot interpret anything written. This learning disability is inherited on chromosomes 6 and 15.

Parents should watch for signs of speech and language learning disabilities in their children. Keep an eye out for difficulties identifying letters and persistent letter reversal. Children with speech and language learning problems can't understand that the word "cat," for example, is made up of three separate sounds put together. They also cannot comprehend complex words. Some children compensate for their learning disability by relying on whole word recognition and their memory. This becomes a problem when they come across an unfamiliar word and can't sound it out, or when their reading becomes more complicated than before. Speech and language disabilities can frequently be caught early and diagnosed while the children are in kindergarten or first grade.

Nonverbal

Nonverbal learning difficulties fall into a higher cognitive abnormality. Children with this disability experience spatial orientation problems, such as not knowing their left from their right or difficulty with reading comprehension. They can read well, but not remember what they read 15 minutes later or put complex paragraphs into context of what they knew before reading. Brain pathways allowing such comprehension are compromised in such children. They also exhibit a poor visual memory and poor handwriting. Children diagnosed with a nonverbal learning disability may write well, unlike a child with an expressive language disorder, but their handwriting is not readable.

Attention Disorders

Many people know these disabilities by the names attention deficit disorder or attention deficit/hyperactivity disorder. Frequently such children are put on drugs like Ritalin. Occasionally children with attention disorders experience other problems contributing to inattentiveness, such as a speech and language dysfunction or nonverbal disorder. Children may get frustrated and jittery because they're not learning efficiently and need to direct their attention elsewhere. Consult a pediatric neurologist for a definitive diagnosis.

Pervasive Developmental Disorders

Parents can easily identify the three components of the autism spectrum disorder: lack of eye contact, inability to relate socially or inappropriate social interaction, and unusual repetitive interests that exclude other activities. Any or all of these early signs should prompt a consultation with your family doctor or pediatrician. The doctor may want to make sure that the child does see normally if you notice a lack of eye contact.

If your child has been having difficulty at school or exhibiting any other sign of a learning disability, such as losing his place while reading, holding his place with his finger, transposing letters or words while writing, writing illegibly or rereading words or lines, first consult your eye care practitioner. Work with your doctor to ensure that all three parts of your child's visual function are working properly.

What to Do About It

If a visual dysfunction is part of your child's learning difficulty, special lenses or vision therapy may help. Should your child's visual function not be an issue, ask your eye care practitioner for referrals to the appropriate specialists. Visit your family doctor or pediatrician as well for more information on diagnosing your child.

Also keep in mind that children with learning difficulties may experience emotional problems as well, such as depression, low self-esteem, anxiety and stress. Reassure your child that help is available and he or she is not stupid. Many children with learning difficulties have above-average IQs and simply process information differently from their peers.

By Gretchyn Bailey.