How can I raise a problem with fogging lab goggles without being treated as refusing to wear them?

The numbers on the measuring cylinder disappeared behind the fog on my goggles. My lab partner said, "Just lift them for a second." I didn't. I told the teacher I couldn't read the scale and stopped handling the equipment.

I'm sixteen, taking school chemistry. The loan goggles press awkwardly over my glasses, and by the middle of the last two practicals I couldn't see clearly through them. The teacher reminded me that goggles are compulsory. I agree; I was trying to explain why I wasn't measuring anything.

My partner finished most of the task while I waited. Now she thinks I'm using the goggles to avoid the practical work. What can I say before the next lesson to get an approved fit or another safe arrangement sorted out, and how do I explain the missed work without making my partner responsible for fixing the equipment?