Some children simply find it difficult to track along the lines and can lose their place when reading. The yellow window focuses their attention to the line they are reading.
Sometimes they are given when a child is diagnosed with Erlans Syndrome, where the black on white text is too harsh and gives the child visual problems. Children can be given the coloured ruler things, or even complete coloured overlays to use when they are reading or using printed black and white material.
Lots of teachers and TAs have experience of some children finding them useful and therefore will offer them to see if they do help. Some of the children in my class use them this year.
Most people find that text seems easier to read when a piece of transparent coloured plastic is laid over it. I've experimented with various colours and many children. They all declare that one colour or another makes the print stand out more. I like blue or green. Frankly I am sceptical as to whether this indicates anything at all, apart from the fact that black print on bright white paper can be visually stressful because the white is so very glaring
My dd1 has trouble keeping track of which word/line she is reading. She didn't before her epilepsy/medication started. Her epilepsy (absences) seem to have stopped now after 1 year but she is still finding reading difficult. Do you think using an overlay ruler thing might help?
<and why hasn't school suggested this before now???>
A reading ruler would probably help as it would keep her tracking the words from left to right and so help to strengthen the eye muscles used for this (reading, not being a 'natural' skill requires that these muscles are 'trained'.). Finger tracking under each word could be equally useful. The problem I have with reading rulers is that most of them disclose only one line of text at a time, so the tracking from the end of one line to the beginning of the next is made more difficult. Though I have seen them with a wider window which discloses two lines at a time.
A Behavioural Optometrist assessment might be useful.
I agree with maizie that just because school have giver her one, doesn't mean she has vision problems - but the only way to tell if she has vision problems would be to get her tested by a Behaviour Optometrist
They test for many things including eye tracking problems. Most of which can be easily fixed.
And obviously, if she does have vision problems, it is far better to cure them, then to use a ruler as a compensating strategy.