As a practical joke, I’m making an eye test chart for a friend. However, apparently there is no “one standard” for font sizes on an eye test chart (called a Snellen acuity test chart), and the details are a giant secret.
Well, for anyone who has ever wanted to make an eye test chart, HERE are the specifications.
| Warning:
This is not medical advice – always consult a licensed medical professional who will use actual medical equipment. My version of the “eye chart” constitutes a joke and is not intended for medical use. |
First of all, there is a free OpenType font called “Optician”. Google for it, download for free, and put it in your Windows/system32/fonts or /usr/share/fonts/opentype folder.
Second, here are the font sizes:
| Row | Distance | Font Size | Sample (size only) | Symbols | Char Spacing | Spaces |
|---|---|---|---|---|---|---|
| 1 | 20/200 | 155pt |
A
|
1 | n/a | n/a |
| 2 | 20/100 | 102pt |
A
|
2 | 84pt | 2 |
| 3 | 20/70 | 72pt |
A
|
3 | 57pt | 2 |
| 4 | 20/50 | 52pt |
A
|
4 | 39pt | 2 |
| 5 | 20/40 | 41pt |
A
|
5 | 32pt | 2 |
| 6 | 20/30 | 30pt |
A
|
6 | 31pt | 2 |
| 7 | 20/25 | 26pt |
A
|
7 | 24pt | 2 |
| 8 | 20/20 | 20pt |
A
|
8 | 18pt | 2 |
| 9 | 20/15 | 15pt |
A
|
8 | 25pt | 2 |
| 10 | 20/13 | 12pt |
A
|
8 | 20pt | 2 |
| 11 | 20/10 | 9pt |
A
|
8 | 16pt | 2 |
- Font Size – set your font size to this, for each row
- Symbols – number of letters on each row
- Character Spacing – Set your font size to this, and use TWO spaces between letters.
For example, on row 5:
- 5 letters
- Letter font size: 41pt
- Spaces font size: 32pt (use two spaces between letters)
Congratulations! Now you can make your own eye chart whenever you want, and it’s no longer a secret.