Font Size

Choosing a font type and size.

Parents regularly ask how to select the correct font size for their child, and we know that some have had the benefit of an experienced teacher of the visually impaired to help them with this, however others have not. Children may become more fluent with their reading or read at a faster pace when the font size etc is perfect for them.

In a recent meeting of parents with children who have CVI, one mother suggested 'do it yourself'...

Start with paragraphs you know your child is comfortable with, and print a single paragraph in the middle of a plain white piece of paper. There are three things to consider:

  • Font Type
  • Font Size and
  • Spacing - between letters, words and lines.

Your child may not simply be able to answer which one they prefer, because they don't know, so you must observe them, and may have to play around with it a little. If one size / font / spacing seems more challenging, you will need to figure out which of the three (or all three?) needs changing. Once you have worked it out, then you can tell everyone, particularly the school. And don't forget all the other stuff that is regularly printed on school work sheets like pictures, graphs etc. That may make the page harder to read too.

Mary who has CVI says...

It took a while for me to work out that I didn't actually need the font size to be too much larger than normal. In fact N12 or N14 font size is fine, as long as the space between the lines is set to either 1.5 or 2. This makes it much easier for me to read longer passages of text. I also find different font types are easier to read than others. For instance, Calibri and Arial are good. Whereas more cursive font styles are more difficult to read.

(Re-read this text in Mary's chosen font and spacing in the box below)

For Mary, the space between the lines was key to reading comfortably.For Mary, the space between the lines was key to reading comfortably.

Janet Harwood is the Chair of Trustees of the CVI Society and a teacher of the visually impaired. Janet is highly experienced helping understand and assess the optimal font sizes for children with CVI.

Janet has suggested the following:

Where to Start
You may have been given a 'near' acuity measurement from an ophthalmologist, optometrist, paediatrician or Qualified Teacher of the Visually Impaired (QTVI) for reading and close up work. I use this as a guide and starting point, but upon assessing children have often found that their actual comfortable font size may be smaller or larger than would be expected. In any assessment environment, a child can feel stressed or uncomfortable, which may reflect in how they perform.

I need to have an idea of the child's current comfortable reading level, and ask the parents for a book that they either find easy to read, or is slightly lower than their current reading level. I need to be careful however to avoid text that may have been memorised, so I also ask for familiar words. I then make up some sentences specifically for each individual child.

I type up a passages of varying lengths using words the child is familiar with, and depending on the child's age, ability etc. I do not set them up to fail before they start, many are quite crushed by their reading experiences.

This requires preparation.

I then look at fonts, I like century gothic as slightly larger and 'a' is easier to read.

A common font in primary schools is comic sans which is also fine.

Arial, verdana and calibri are also worth trying

Spacing May Be As Important As Size
I then play around with spacing between lines and even characters if necessary, everything is in bold too.

Some organisations have offered parent's guides to help decide font sizes but do not factor the impact of spacing, thus a parent may choose a very large font, when a much smaller font with optimal spacing may be much more comfortable to read for the child.

Look at the fonts in the box above. With line (1) the lines that form the black letters are thick, in fact thicker than the gaps between each letter. The line thickness may be easy to see clearly for the child, so they can easily recognise the word 'I' in the sentence, however because the gaps between the letters are more narrow, the letters start to merge, and the child finds reading the words difficult, because they lack clarity.

One solution to this problem is to make everything bigger, as with line (2). The gaps between each letter are now big enough for the child to see each letter clearly, but Janet's experience is that this can be too big for the child. Key is to find the optimal font size for comfortable reading.

Line (3) is a smaller font where the line and gap widths of the letters and gaps between letters are similar. This may be more comfortable for the child. But it would be worth trying a font with wider spacing, like in line 4). If the child responds well to this font size, it is worth seeing if they prefer it larger or smaller. It may be that a child is thought to need line (2), when actually reading would be more easy and comfortable, thus enjoyable, with line (5).

In addition to the spaces between letters, consider further the spaces between lines and paragraphs, as Mary explained above.

Janet continues:

I ask the child to read and assess speed and fluency, and most importantly, comprehension. This is why the vocabulary needs to be at the right level for your child. If their reading speed becomes slower and the child appears to struggle, I adjust again. I also assess for maximum comprehension and chunk the work, to try and find out how much the child can remember and answer questions about. It is amazing how many 'fluent' readers spend so much time concentrating on decoding and cannot recall what they have read, we all do when we are tired, but in a class situation this may be put down to cognitive issues.

I try to assess reading for each child a couple of times, including when the child is tired. This can be key, as often people will go for a smaller size which may not be big enough after a hard day. I also ask the child which they feel comfortable with when we are narrowing it down.

For some who do not struggle as much, covering up some of the print with a piece of card like a big bookmark helps them to keep their place (covering over the text which has just been read above the line the child is reading lets them identify the first word of the next line without difficulty, but gives the same benefits as a card under the line, by acting as a guide and removing the same amount of print clutter). find many do not like typoscopes (letter box type aids), but will use a bit of card. I even get them to use a finger if it helps them to locate each word.

Parents need to engage their child's teachers and Qualified Teacher for the Visually Impaired, and other professionals. If you need changes to be made, not just at school, but also with exam boards, the parent's own view may not be considered enough.

If you, your child's teacher, QTVI or other professional would like to discuss this issue further please contact Janet Harwood by emailing or via the CVI Society contact page.

Important Note
Our advisors have noted that the font size in reading books aimed at seven or eight year old children is often significantly smaller than the font size in books aimed at younger children. This reduction in font size does not necessarily match the pace of the child's visual development, and they may find it hard to read the words because they have jumped from big enough print, to far too small print that's too closely packed, too quickly. For these reasons, some children around the age of seven or eight seem to lose interest in reading.

One mother wrote:

This is definitely the experience we had with our son who is 8 and a half. About a year ago he was completely fed up with reading and was so anxious about it. It was really hard to get him to read anything, so we got him a Kindle and increased the line spacing between the lines (because he complained that the lines kept running together), as well as the font spacing.

He is now a completely different kid when it comes to reading. He just started on the sixth Harry Potter book two days ago and is already up to chapter 10. He just wants to read all the time and can flick between reading on the Kindle and reading print books easily.


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