That is interesting long nosed vine snake have a horizontal iris. Preditors usually have a vertical iris because it allows them to focus better on their target.
For example goats have a horizontal iris because that allows them to see over a wider range, protecting them better versus preditors.
I always wonder how the nature of their eyes looks like each time I look through it. How about camel with its three layers structure? What a creation!
@mathowl I'm glad to read from your end and thanks for adding to the knowledge domain