I'm really digging virtual reality, and I thought that a IPD measurer was lacking on Thingiverse. Here is my take on that function.
It's graduated from 55 to 80 mm.
To use it, choose something really far (at least 50m or 164ft) and well lighted. Watch that object through the holes in the measurer, and slide the moving part until the images in each of your eyes are identical. Read the distance on the scale.
Dragons not included.
!!! DISCLAIMER !!!
THIS IS AN OBJECT YOU NEED TO PUT CLOSE TO YOUR EYEBALLS.
USE AT YOUR OWN RISK.
IF USED ON A KID, AN ADULT NEED TO CAREFULLY SUPERVISE THE OPERATION.
eMotion Tech PLA
Post printing step
Depending of the printer, it may need some unburring. Take care to orient the moving part properly.
For extra readability: you can let the engraving soak up some paint. Then sand it, and apply some clear coat.