Binocular Vision Problems

Studies have shown that children with dyslexia often also have binocular vision problems (also called convergence problems). This means that their eyes don't work together very well. For example, when they're reading each eye may be looking at a different letter.

A simple test to see if your child has binocular vision problems is to see if they read better with one eye covered.

In extreme cases this problem can make the text blurry or appear to move. It appears to move because the brain is receiving two different images.

Reversing letters like b and d

When dyslexics read they make excessive eye movements. Their eyes wobble - they constantly move left to right, and right to left. So they read 'b' both from left to right and from right to left - which is what makes it look like a 'd'.

Skipping words and lines when reading

Because their eyes move too much, it's very easy for them to skip words and lines.

Very poor spelling

Dyslexics don't look at every letter when they read. You can read if you only look at a few letters in a word. But to spell correctly you need to remember every letter.

Difficulty copying off the board

Copying off the board requires looking at the board, then at your paper, then back again. If it is hard to control your eye movements and focus, then it will be hard to go back to the correct place.

Words appear to move, or are blurry or double

Most dyslexics have focus issues. When one eye is looking at one letter, the other eye is looking at a different letter. This means their brain receives two images at the same time. If the brain alternates which image to process, it causes the text to appear to move.

Alternatively the brain can take the two images and use both of them, which makes the words look blurry or double.

Not understanding what was read

People without dyslexia look at around 150 points per minute when reading. But people with dyslexia look at around 1,000 - mostly in the wrong place. So they spend a lot of brain power filtering out the wrong points. Then they don't have enough processing power left to understand what they've read.

Reading slowly

Because dyslexics make too many eye movements it takes their brain a long time to realise what the next letter / word should be. So they keep rescanning the text until their brain can make sense of it.

Getting eyestrain or tired when reading

When you read, you need to refocus your eyes every time they move. For a dyslexic person this can be around 1,000 times per minute. No wonder it is tiring and can cause sore eyes.