Enterbay does that for their Bruce Lee figures but it adds an extra $50 to the price tag
For the versatility that offers, I'd spend that. Instead, I'm spending $50 less on this Joker and the eyes are stuck in a position I don't want them to be and I'll spend that extra $50 to have them permanent painted where I want them, where for $50 to the manufacturer, I could potentially get an infinite ammount of eye poses out of my figure. It's smart money in my mind. You get the realism of having the eyes not looking dead on straight, but you get the flexibility to have the eyes looking however you want instead of the manufacturer essentially choosing your pose/display options for you with a choice in painting.