i have 3 cats 2 go out 1 stays in the 2 that go out have been showing the thired eye well i dont know but one male neudered 4 years old had been going out its been 2 or 3 weeks ago hes urin is crytal like at first it was a tespoon but i been keeping hem in its moor regular now but the layer of skin that covers the eye when there sick will go down then back again in a few days now the female 2 years has came home today showing the third eye a little i walked the neigbor hood seen 2 contaners of antifreez siting out but i just dont know i have a 3rd cat she spaded an stays in she does not show the thired eye