Putting a patch over a child’s normally seeing eye simply makes the brain use the image coming from the amblyopic (some people call it ‘lazy’) eye. As long as a patch stays on for at least 2 hours in a day the brain will begin to develop the visual ‘circuits’ that last for the rest of your life. The earlier and more that patching is done the better the vision that will be achieved.
No, not when trying to make them use a poorer seeing eye. Children are pragmatists, they will find a way to peek around those options for convenience sake. The only way that works for most children who have significantly poorer vision is to use an adhesive patch.
If you qualify for the enable subsidy then you can have patches provided free of charge. Some patches are more expensive and may only be available free to local customers. Some optometrists may choose to charge for patches anyway. If you can’t get the subsidy and don’t mind a plain white patch then they are easy to make yourself using 3M Micropore tape which will be available from your local chemist in a 2 inch wide roll.