What are good general typeface principles based on target audience age?

Question

Everyone knows that as people get older their vision deteriorates.

At 20 years old, few have trouble seeing and reading 8 or 9pt type in print or 10-11px type on the web. However, the older an audience gets the larger type needs to be, and the more leading needs to be adjusted, for them to read comfortably.

Knowing the target audience's average age helps to design pieces appropriately with this in mind.

• What are good type settings to use in print for an audience 20-40 years old? What about web type sizes?

• What are good type settings to use in print for an audience 40-60 years old? What about web type sizes?

• What about above 60 years old?

• Are serif/sans serif a factor with age or is readability more universal where this is concerned?

Answer 1

That's a can of worms you're opening here. I'd say the jury's still out.

As far as font size is concerned, this study (pdf) concludes that

there were no significant differences (for sizes 6-16) in reading performance or accuracy due to either passage length or age there was variation in subjects’ preferences on the text sizes used.

They compared a group of age 18-29 against one of 61-78 and used PDAs as test material. Predictably, older people prefer larger type, but they seem to be as accurate in reading it as youngsters are.

On the contrary, this 2007 study (pdf), involving vision-impaired readers, states a preference for sans serif typefaces between 16 and 18 points, but fails to draw any hard conclusions or advice for typography for the 'general', non-impaired populace.

A collection of academic evidence articles can be found here, on a blog that is dedicated to the research into legibility as a function of typeface. Looks like a lot of articles are worth the attention. The blogger himself seems to draw the conclusion that there is no 'ideal' or 'most legible' typeface, as per his article on the blog's front page.

Another extensive literature study on the sans vs. serif debate doesn't find any significant difference, and seems well worth the read as well.

Moreover, there's more factors to consider than just type size and whether the typeface has a serif or not. Variables like relative x-height, openness of the counters, leading, tracking and font weight are making this even more of a wasps' nest.

All this is just a half hour's worth of Googling and scanning, and it seems I haven't glimpsed the bottom of the rabbit hole yet. If anything, I'll draw the conclusion that your question deserves a close vote for 'too broad'...

Answer 2

I don't think the demographics split quite so cleanly every 20 years and then have a corresponding font size to go along with it.

In general, most print type hovers around the 9pt-11pt size. That's likely too small for those getting older, hence the reading glasses market.

For the web, the ideal type size for everyone is:

1em / 100%

That would be the default size set up in the person's browser/device. In theory, the user would have their system set up to the font size they prefer and by using the above you have accommodated them.

Alas, that's more theory than reality. The problem is that browsers default to 16px as the default size, which most of the internet's designers felt was too large, so you are more likely to see type online around the 11-12px mark. As such, all those people that know how to set up their browsers likely have purposefully already made their default font sizes larger to accommodate, so 1em may actually come out cartoonishly big.

Are serif/sans serif a factor with age or is readability more universal where this is concerned?

Nope. What research there is on readability of serif vs. sans serif is vague, at best. For the most part, people are comfortable with both.

Answer 3

I'd like to add some points to the answers.

The issue of age related changes in refraction (the possibility of the eyes to bend light rays) is mostly related to the state of the crystalline lens - organ inside the eye which can bend light rays depending on the object's distance (this function called accommodation). In young people the lens is gel-like, but the older we became the harder the lens became and consequently it partly looses its possibility to bend light rays (loss of accommodation). This phenomenon is called Presbyopia (the vision of older people).

The subject affected by presbyopia cannot refract well and the nearer the object the greater refraction needed, thus the subject move the object away by hand (or moves the body). As a consequence the object seems to be lesser in size and in this case the magnifying glasses come for help.

One interesting fact about presbyopia is that it depends on how far the man/woman lives from the equator. Closer distance to the equator causes the presbyopia to appear earlier in lifespan - i.e. in India the age of onset is 37, but 46 in Norway. This phenomenon is temperature dependent. The higher the ambient t, the earlier the onset of presbyopia.

Thus, you should know/track not only the age of the user, but also his/her living location. i.e. Haiti habitants rarely have presbyopia because of shorter life there, so they roughly enjoy just a regular vision.

Probably, this hypothetic point suggest you increase the font if the user comes from India, or leave it regular if the user comes from Norway etc.

Additionally, most people using PC's in older ages wear reading glasses, so the issue of the font size is frequently treated already from their side - the reading glasses are just magnifying glass and small font looks larger in them.

Answer 4

My two cents here (a long comment rather than an answer). I don't think this is a matter of age, unless you can restrict your user sample to a certain specific location in space and/or time.

Some people might prefer bigger types because they are culturally biased towards them. Others might go for small ones, even if they make reading difficult (me). Eye sight varies from person to person, the total percentage of (for example) Americans that use some form of corrective lens is 75%. That's a large number. Even if the vision is 'corrected', I can't stop thinking of my mom when she had eye laser surgery and the first thing she said when she saw me: You look so defined!