Contact lenses for cosplay
Why?
Because your character is badass and has red/gold/green eyes, and your eyes are neither red nor gold nor green 
Procedure
In Australia you need a prescription to get contacts.
- Visit your optometrist, they need to check that contacts are suitable for your eyes (ie. won't make you blind for some reason). This is largely a formality.
The optometrist produces a prescription. This roughly says that you're okay to get contacts, and also how messed up your eyes are if you're myopic/hyperopic/astigmatic
- Get a copy of the prescription from your optometrist
- Most people get contacts from their optometrist, that's not a bad time to ask about proper care and usage of lenses, maybe ask for a trial pack of something
- Now that you've got the prescription, you're also free to get your lenses from wherever else too
Good things to know
- The optometrist visit is covered by medicare
- It presumably has a nominal dollar-value, but you can't get it by paying for it, it's just covered
- Getting contacts online is usually cheaper, but there's roughly a 4x incidence of infection in people who do
- Citation needed for the 4x figure
- This doesn't say anything about the absolute risk of infection (ie. 1-in-4million to 1-in-1million is kinda no big deal)
- This infection risk is mostly due to poor hygiene and not having been instructed properly