Those who wear prescription glasses full-time are in luck. OTG, or Over the Glasses, goggles are a solution to your need to wear both. OTG goggles have more room between the face and the lens, and this offers the room needed for prescription glasses.
Although, there are also prescription ski goggles available as well. If you think that you would be more comfortable without your glasses underneath, this would be a great option for you.