I was rather annoyed when 3 leading ophthalmology journals turned this down, and even without review proper! Today the paper has appeared, finally:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0147803

Thus the old adage that you should not give response feedback to your patients when assessing #visual  acuity is wrong, at least if you can automate feedback so easily as with FrACT

https://michaelbach.de/fract/

I admit to being proud of this little thing – It helps to keep your patients cooperative.