Leopard Limitations

Milk is something, apparently,
That leopard cats just cannot see.
How does that work? How can that be?
Is it just milk that they cannot see,
Or is it everything dairy?

I’ve found nothing that can clarify.
The internet does not know why.
Just that no matter how they try,
It can’t see milk, that leopard’s eye.
I suspect this fact might be a lie.