Many people have visual impairments
The World Health Organization reports that 2.2 billion people have visual impairments of some kind; that's 27.4% of Earth's population of 8.025 billion people. Google also just told me that 25.3% of Americans under 18 wear glasses or contacts, and that 92.4% of Medicare beneficiaries aged 65 or older wear glasses. Look around in the next meeting you're in; how many of your colleagues wear glasses? And of course some others may be wearing contacts.
When I was a 20-something web designer, a wonderful account manager announced to the room during a creative review, "My old eyes can't read that small gray text." I thought she was kidding, or at least exaggerating, but I generally got her point.
It's easy to forget about minor visual impairments
Now that I'm older, I often cannot read small gray text — sometimes even with my glasses on. I'm not at all someone who would be considered severely visually impaired; my glasses prescription isn't very strong. But tiny text on the web is difficult for me to read, and it's often annoying and frustrating; it definitely creates a poor user experience for me.
I'm much more likely to bounce out of a site that has tiny text. I notice myself doing this fairly often if I'm searching for a topic and end up on a site with tiny text when I know there are likely going to be plenty of other sites that cover the same thing. Boom, go back, hit the next result.
I often joke — and I wouldn't be surprised if you've heard other people make the same kind of joke — "I'm 'takes-a-photo-of-the-instructions-and-zooms-in-to-read-them' years old." And I need to do this even with my glasses on, for all kinds of printed things.
Think about users who are colorblind — that's about 5% of all people! Think about older users. Think about users who don't have their glasses handy. Think about users whose eyes are tired at the end of the day. Think about users who may have a headache. Of particular importance if you work in pharma like I do: think about users who are experiencing health problems, and are stressed, or worried, or distracted, or experiencing discomfort. We should make all of our content as easy to engage with as possible for these people.
Visual impairments aren't the only thing to consider
Just ending with a funny story here: The smallest body copy I've ever seen in a website layout in my entire career (this was around 2012) was for a website for a medication for people with migraines! Imagine trying to read ultra-tiny text while you're dealing with a splitting headache. Super tight leading too! Sheesh.
Let's be mindful of all of this and do better for users!
– Manning
Questions/comments? Feel free to contact me at manning@manningkrull.com. I update these articles pretty frequently — best practices evolve over time as the world of digital quickly changes, and I always welcome insights from others.