There is yet No DNA test for PRA eye research of CsW available
More info about
EVCO eye research for dogs you can find
HERE
In most cases an EVCO research will be enough.
When a dog has specific eye problems an owner can also let make
E.R.G.
In my country only the university is doing this for research.
Info about what is an E.R.G. , you can find
HERE
Sorry , but I could not find info about E.R.G. for dogs in English language!