A Brief History of Optotype

You’re sitting in your eye doctor’s office and they pull out a chart of what appears to be a random selection of letters. You breeze through the first few lines, but by the bottom you’re starting to second-guess yourself. Is that an F or a P? Or maybe an R?

At this point you may be wondering: Where did these letters even come from? And who chose them?

With curiosity as our guide, we decided to dig deep into the history of optotype and how the Snellen Chart went from medical innovation to standard practice and all the way to pop culture ubiquity.

The Origins of Optotype

While glasses and other corrective lenses have been around for thousands of years, it wasn’t until more recent history that doctors have a had a standardized system for determining prescriptions.

The idea for the modern eye chart began with German ophthalmologist Heinrich Küchler. In 1835, Küchler cut images of various objects and animals from calendars and almanacs and pasted them onto a sheet of paper in decreasing size. Because it was difficult to control the consistency of the style and weight of these images, Küchler also published a version of the chart using blackletter text set in single lines in decreasing size in 1843.

Küchler’s chart was not widely adopted and, in 1862, Dutch ophthalmologist Herman Snellen developed his own version of the chart that is still the foundation of what is used today. Snellen’s first chart consisted of dingbats (squares, circles, plus signs, etc.) but, like Küchler, he eventually decided that letters would be easier for patients to identify and describe consistently. Unlike Küchler, however, Snellen believed that monoline letterforms of consistent size would be easier to read and he developed his own typeface, now referred to as optotype.

Herman Snellen built each letter of his optotype on a rigid 5×5 grid so that each letter is mathematically consistent and takes up the exact same amount of space.

While traditional letterforms use varying widths and heights to give the appearance of consistency, Snellen built his optotype on a rigid 5×5 grid so that each letter is truly mathematically consistent and takes up the exact same amount of space.

In 1959, Dr. Louise Sloan designed the 10 sans serif letterforms that are most commonly used in eye charts today.

In 1959, Dr. Louise Sloan of Johns Hopkins University created a new optotype with a cleaner sans serif design. Like Snellen’s, Sloan’s letters are formed within a perfect square. Both the Snellen and Sloan optotypes contain letters that were chosen for their easily identifiable verticals, horizontals, and diagonals—C, D, E F, L, O, P, T, and Z for Snellen and C, D, H, K, N, O, R, S, V, and Z for Sloan. Sloan’s letters are considered better for equal legibility and are particularly effective at identifying astigmatism. Sloan’s letters and variations on them are still commonly used in eye charts today.

How To Read a Snellen Chart

Modern Snellen charts can vary in the number of lines, length of lines, and typeface used, but most charts typically contain 11 lines that decrease in size by 25% each line. The lines of text are sized based on what the average person can read at a distance of 20 feet. Someone who can only read the top line of text can see at 20 feet what an average person can see at 200 feet, meaning they have 20/200 vision, which is considered legally blind. While 20/20 is often considered “perfect” vision, it actually means that someone is on par with what the average person can see at 20 feet. Some humans actually have 20/15 vision and many animals have 20/10 or even 20/5.

The lines of text on a Snellen Chart are sized based on what the average person can read at a distance of 20 feet.

Today, many eye doctors prefer to use the LogMAR chart developed by Ian Bailey and Jan E. Lovie-Kitchin in 1976. The LogMAR Chart uses Sloan letters in an inverted pyramid and is considered more precise than the Snellen Chart. Most doctors have also traded in their paper charts for backlit displays that provide better contrast.

Other eye charts include the Tumbling E and Landolt C charts that are used for children and adults who aren’t able to read and the Jaeger chart which measures near-vision acuity and features paragraphs of text rather than letters.

While the original Snellen chart may be falling out of use, it has taken on a new life outside the doctor’s office. The simple design makes it endlessly riffable and designers continue to find new ways to reinterpret it. So whatever form the eye chart takes next, it’s certain that Snellen’s optotype will remain a memorable intersection of medicine and design.


“Who Made That Eye Chart?,” New York Times
“What Are Optotypes? Eye Charts in Focus,” I Love Typography
“What’s an Eye Test? Eye Charts and Visual Acuity Explained,” All About Vision

Designers Tackle the 36 Days of Type 2018



Each day a new character, and in our case, a new designer as we passed around the alphabet to explore type, animation, illustration, storytelling and more. Designers and illustrators around the world participated in 36 Days of Type by posting to instagram and connected with the #36DaysOfType hashtags. We decided to tackle the challenge as a team this April and May. Repetition invites creativity and crafting. We also invited the opportunity to try new techniques. We stuck (somewhat) to our original color palette and prescribed dimensions and dove in.

Each designer chose their favorite letter and gave some background. (Check out this reference for a quick guide on technical type terms.)



I always appreciate projects like 36 Days of Type for creating opportunities to try new tools and solutions in a design setting. I used much of that opportunity to explore computer-generated three-dimensional design and animation. While there are quite a few examples of this in the library of type we created, this “Inflatable C” is one of my favorite results of that exploration. While it’s quite minimal, it shows off some of the new options that the third dimension can create for designers like convincing depth in the subject and a more robust use of simulated physics. Along with all of that, this piece just makes me think of summer.



The double-story (or looptail) “g” is one of my all-time favorite letterforms. Even though it’s mostly superfluous, difficult to write and unrecognizable to the majority of population, I love how it seems to capture all of the personality of a typeface and its designer. For this illustration, I wanted to take full advantage of the letterform and do something playful to link the two counters. The shapes reminded me of pools of water, so I turned them into little ponds and, in the name of the letter “g,” added a goldfish leaping between the two. It’s a quirky little fish at home in a quirky little letter.



I think the most interesting part of a capitalized J is its arm. Many sans serif fonts do away with it for simplicity’s sake, but I like the way it can balance the otherwise asymmetrical form. I started with a grid paper sketch to articulate my idea. On paper I could visualize how to fit the two scoops of each J shape together and experiment with softly curved terminals. Then I moved to the Procreate app for iPad. I used a chalky brush to give body to the letter, and then used the eraser tool to define the edges and corners. Procreate allows layers so I could add illustrated florals between the tall, narrow J and the more squat, overreaching J tucked in where I wanted—and still have each piece editable. I fit organic shapes and ornaments in and around the ribbons to complete the bright composition.



One of my favorite aspects of the 36 Days of Type project was that it gave us freedom within a rigid structure. That sounds like a contradiction but it’s not—the project was completely open-ended, with no direction or client feedback, but at the same time, the content was inflexible (the letter of the day), the timeframe was limited (one letter each day) and as a team we also chose to limit ourselves to a common color palette. Freedom within constraints can lead to remarkably creative solutions.

For some of my letters I tried to build a formal letter shape, conforming to typographic traditions and crafted for legibility and grace. This K is an example. After looking at other K shapes in a variety of fonts and calligraphy I identified some of the geometric “bones” that I wanted to build my K around.

In other letter explorations, I chose a more conceptual approach. I thought it would be fun to build the letter P shape out of large, oversized pixels. In the animated version of this “P is for Pixels” composition, I created a digital sort of shimmer by slowly fading each block between a few different values of blue.



I love projects that require a series of explorations around the same prompt. Eventually your typical approach to the problem starts to feel tired and uninspired and you are forced to try something you might not normally consider. 36 Days of Type was that sort of project for me (even in just the 7 or so iterations I completed as part of our team approach).

Part way through my initial explorations began to lose their initial spark and I started looking around my environment at home for inspiration. We have a variety of patterned fabrics and other materials around the house, from curtains to coasters, and while studying them one evening I started to imagine how those patterns would look in motion. One pattern in particular happens to feel very much like a grid of geometric letter X’s.

Once I tested the idea with X, I wondered about the same concept applied to a different pattern-letter combination. It was interesting approaching the problem from the other direction the second time around, starting with a particular letter or number and trying to discover it in an already existing pattern.

You can see the whole set from the MJM design team on our Instagram account or by watching the video below!

Happy National Coffee Day!


How do you take your coffee? Steaming hot, black, with cream, sweetened, over ice? Whatever your preference, coffee is a powerful and delicious, tool for building relationships.

Sharing a pot of coffee is a morning ritual at the office. We enjoy beans roasted down the road by our friends at The Breaks. So is meeting over a cup at Queen City Bakery or Coffea. We even map out the progression of economic value using coffee beans from their raw, harvested form through a full concierge-like coffee experience.

We think coffee is pretty great, but it’s even better with you (and donuts). Download our original Coffee Coloring Page. Color it in, take a photo, tag us and we might just have to have coffee with you sometime.


Can You Read Me Now: Choosing Fonts for Cataract Patients

All over the country, doctors and their teams work hard to restore vision for their patients. The ophthalmologist’s toolbox is outfitted with trusted, life-changing procedures and techniques like advanced cataract surgery with lenses that help patients rely less on their glasses. Eye care professionals help change their patients’ perspective by making the world brighter and clearer.

At MJM, we help provide clinics with educational tools, brochures, ads and websites that cater to people with cataracts. One of the tools in the designer’s toolbox is typography. From signage and directions to brochure and website fonts, legible type can set the tone for a patient’s experience.

Here are a few things we keep in mind when we make typography decisions for audiences with limited vision:

1. Choose high-contrast colors

Cataracts prevent some light from reaching parts of the eye that create an image. When text color is too similar to background color, letters and words may become muddled and difficult to distinguish. Black or very dark text on a white background is most legible.

Graphic about choosing fonts for cataract patients - choose high contrast colors

2. Choose full-bodied letters

Fonts with a tall x-height, wide letters and long descenders and ascenders are easier to discern because they take up more space and create shapes that are easily recognizable.

Graphic about choosing fonts for cataract patients - choose full-bodied letters

3. Used mixed-case type

ALL CAPS not only appears to shout, but it also can make text harder to read. So can italics. Our brains read words as shapes rather than identifying individual letters. And since we are more used to reading in sentence case, our minds can process those words more quickly.

Graphic about choosing fonts for cataract patients - use mixed-case type

4. Choose moderate stroke contrast

Find a happy medium between uniform thickness (like Futura and other trendy sans serif fonts) and super high contrast. To someone with blurred vision, an ultra-thin stem can virtually disappear from the page.

Graphic about choosing fonts for cataract patients - choose moderate stroke contrast

5. Avoid condensed fonts

They narrow the natural shape of letter forms to take up less space. But, this also means that they are more difficult to read.

Graphic about choosing fonts for cataract patients - avoid condensed fonts

6. Use serifs for paragraphs

Serifs are like little signposts telling our eyes where a letter begins and ends. In a paragraph, they direct our eye traffic as we dig into longer copy.

Graphic about choosing fonts for cataract patients - use serifs for paragraphs

7. Stay positive

Negative text (white on a dark background) gives the illusion that the letters are thinner than they actually are, making them more difficult to read.

Graphic about choosing fonts for cataract patients - stay positive

8. Size matters

Twelve-point font looks different for Futura than it does for Brandon Grotesque. Printing an example proof can help tell if the font is going to be large enough.

Graphic about choosing fonts for cataract patients - size matters

9. Embrace space

Without enough space between lines, letters and around the text block, legibility is compromised. There are a few ways to do this:

  • Increase leading (space between lines) to about 1.5 times the normal amount.
  • Increase tracking (space between letters) so letters are less likely to visually run into one another.
  • Increase the margins to appropriately frame the text.
  • Write concise copy. Adding content to a limited space can compromise legibility. Shorter copy can be compelling, especially when it gets read.

Graphic about choosing fonts for cataract patients - embrace space

Like most rules in design, there are always exceptions. A font with uniform line thickness and low x-height like Brandon Grotesque compensates by increasing the leading (space between lines) without manual adjustment. The font that populates a brochure may not be the best for an outdoor parking lot sign.


A Hand Lettered Alphabet GIF


GIF of a hand lettered alphabet

I drew one letter every day for 26 days last December. The alphabet. Alpha through Zed. The ABCs. I completed the hand-lettered alphabet project just for me. I made a gif of it just for you.

Some letters took a few tries before I came to something I liked. “F” was a fantastic failure if I remember correctly. “X” is all over the place.

None of them would function well in a font. Still, every time I put pen, pencil, or marker to paper, I faced decisions about line, movement, dominance, value, and balance. These design element decisions are important to practice. Letter forms are the perfect tool for rapid iteration, once you get to know them.

Characters are purely symbolic. They have no meaning until people come along and give them something. Still, anyone using the Latin alphabet recognizes that an A is an A; it has a sound, a name, and looks like an angle with a crossbar.

Because an “A” already has a form structure, I have the freedom to add flourish and dimension. “B” forms of the world add curved elements to the challenge. “C”s abandon straight lines altogether. Their personalities are curious and demand attention. When I do it again, they will be different, but never perfect.

Typography for Kids


As a parent teaching my kids about letters, it’s sometimes difficult to know which A to focus on.  What is the Platonic form of the lowercase A?  It may also be an occupational hazard that I want to tell them about serifs and italics and the difference between a two-story “a” and a one-story “a.”  And I’m not alone.  Here are several books that have been put together with the aim of teach children more about the various and sundry shapes that our letters can take.

Bembo is a typeface that was developed in 1929, but was based on the print in a 1495 work from called De Aetna.   The De Aetna type, as it is called, was cut by Francesco Griffo for a printer named Aldus Manutius in Venice.  The modern typeface was named after Pietro Bembo, an Italian poet who wrote a short book about a journey to Mount Aetna.  (That text was the original purpose of the De Aetna typeface.)

Bembo has been very popular for setting books and long texts since the 1930s, but more recently it was the inspiration for a children’s book, Bembo’s Zoo, by Roberto de Vicq de Cumptich.  The author creates a zoo-ful of animals out of the letterforms of the Bembo font.

An even more recent project is The Clothes Letters Wear, by Jeremy Dooley.  It’s a straightforward trip through the alphabet, but each letter is taken as an opportunity to explain and explore the myriad forms of letters.  That project should be available to purchase within the next few months.

One more resource that teaches children about letters, typography and letterforms is a book called Hyperactivitypography from A to Z.  The book looks fantastic, although I have yet to see the printed version–that link will lead you to the full version online.

Crafting Type Workshop

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I’ve been getting more and more interested in typeface design over the past year.  A carpenter needs to know how trees grow and a chef should know something about the origin of the food that ends up on the plate.  In the same way, a designer who works with text and letterforms every day should have a solid understanding of how those letterforms are constructed.

I like the idea of designing a custom typeface that could serve as the unique voice for an organization. There was a time when an author could be identified by the handwriting on the manuscript, but fonts have largely taken on that role. There’s a good chance that I would recognize and associate a font with a brand more quickly than I would recognize the handwriting of a close friend. (I don’t exchange much handwritten correspondence these days.)

Until now I’ve been exploring typeface design on my own by sketching, researching and trying to build a few different fonts, but next week I’ll be attending the Crafting Type workshop in Boston to explore it in a more systematic way.  I’m looking forward to it, and to the new creative directions that will come from this trip.

Clearview: A Study in Legibility

Hard-to-read headlines in a brochure are obnoxious, but hard-to-read highway signs can be a hazard.

For decades the typography used on US Highway signs was a patchwork, each sign maker creating letterforms according to his or her style. Most of the early signs were hand-painted, and painted in uppercase letters because the lowercase is more difficult to paint. Unfortunately, text written in uppercase letters is more difficult to read. (Ask the US Navy.)

For this reason, street and highway signs are now written in a mixture of upper- and lowercase letters. It’s been proven to be easier to read under a variety of conditions. James Montalbano is a type designer who collaborated in the creation of Clearview, the typeface which is now used on most highway signs through the US.  In an interview for a New York Times article on Clearview, Montalbano gave this illustration of why a combination of upper- and lowercase letters is more readable:

If a word is set in all caps, all you will see are little white rectangles,” he said, scribbling a quick “HELLO” on a napkin. The word looked heavy, almost industrial.

But this has a definite profile,” he continued, and then he drew “Hello” again on another napkin, this time in a mix of upper- and lowercase letters, its peaks and curves and dips setting off all the necessary clues in the subconscious. He held the paper in front of me. As he slowly pulled it farther away, the individual letters became harder to read, but the shape of the word remained distinct. “Your brain,” he concluded, “knows the shape of the word.”

Clearview has a high x-height which allows for large, easy-to-see lowercase letters that still retain the unique profile of the word. It also features large counters (the spaces or bowls in letters like “p,” “c” or “o”) which creates visual space without sacrificing the sense of the letter. Take a look at these examples, from the ClearviewHwy field tests:

In design, context is everything.  While Clearview may be more legible on a sign, it would be tiring to read a entire book set in Clearview. One is more legible, and the other more readable. (Although there is now a Clearview Text font.)

Typography: A Matter of National Security

There are some situations where it’s acceptable to write entirely in capital letters. Headlines, titles, epitaphs carved in marble–when the text is brief and when you intend to emphasize a specific word or set of words.  But in general, as a matter of good typography and style, writing in all caps should be avoided.  Lowercase letters make text much more readable.  But don’t take my word for it–ask the US Navy. The US Navy recently sent out a message (written in all caps, according to the BBC) to the effect that official communications can soon be written and sent in a mixture of capital and lowercase letters. Until this point, all naval messages were sent in capital letters.  This was due in part to the technical limitations of some early communications systems and in part to tradition.

But the Navy is now ready to take a step toward better typography, and one of the primary reasons is that lowercase letters significantly enhance readability.  In the official press release last week, James McCarty (naval messaging program manager at U.S. Fleet Cyber Command) is quoted as saying “Lowercase messages are here to stay; they provide a more readable format.”

Plus it’s just bad manners to write in all caps–no one likes to be shouted at. Writing in a mixture of cases is more legible and more expressive, allowing the writer or designer to use the nuances of the written form of our language to dynamically communicate, instead of writing in one loud, monotonous voice.

Written Communication: Avoid Mixed Signals


People evaluate you, and your message, not only by the words that you say but also by how you say them. Before you’ve said ten words, your audience will have formed opinions about your intelligence, your level of education, and your credibility. Whether they ought to form those opinions so quickly and on the basis of so little information is a matter of some debate, but that they form opinions quickly is an established fact.

There is almost universal agreement about what I’ve said thus far when the concept is applied to speaking. There does not seem to be the same degree of awareness when it comes to written communication. The same dynamics come into play when someone picks up your brochure, reads a sign in your office, or uses your website. Professionals who would never answer their business phone with a casual, “What’s up?” have no qualms about putting a sign like this in front of their receptionist:

The typeface used here is called “Papyrus” and has its uses—summer camp, amusement parks, or Roman ruins. But it is out of place in a professional office, where it unintentionally communicates “we are not very concerned about this sign, about confidentiality, or about typography.”

The lettering in this second image, on the other hand, presents important matters in a credible way.

The wording is the same, but the meaning is different.

Your printed material sets the tone for the rest of your interactions with your client or customer.  Take the time to craft the presentation of your message as well its content. You will communicate effectively with your audience and avoid sending mixed signals.