The 2014 version is posted. Here is a link to the 2016 edition:
http://www.pov-int.eu/wp-content/uploads/2016/03/2016-Dt-PoV_Trainer-Handbuch_sec.pdf
[Update: This became a dead link in the first days of January, 2019. However, the 2016 edition can be found in chapters in the following links which we captured in Nov. 2018]
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_8.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_69.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_38.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_57.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_25.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_94.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_64.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_50.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_99.html
https://psychologyofvision.blogspot.com/2018/11/psychology-of-vision-trainerhandbuch_42.html
A translation and analysis of the 2014 edition can be found at these two links:
http://www.newagefraud.org/smf/index.php?topic=4179.msg36673#msg36673
http://www.newagefraud.org/smf/index.php?topic=4179.msg36674#msg36674