How do I check the space between the bottom and back teams?

My friend recently got double eyelid surgery + lower and upper eyelid lift + double eyelid surgery, and she looks like a completely different person. I'm so jealous that I'm thinking about getting it done too, but
 my double eyelids are inline right now, and if I eat ramen, sleep, get tired, or have swelling, they disappear. They'll appear in the afternoon,
 but if you don't see any signs of them appearing, if you get double eyelids or double eyelid lift and do it for about a day, it'll appear again the next day.
 I'm not particularly dissatisfied, but in the case of lower and lower eyelids, she said that if there is no space for the frame, she wouldn't recommend surgery, and even if you do, the effect is almost
 non-existent, so it's better than not doing it. If you don't plan on getting upper and lower eyelids, and only get lower and lower eyelids, how do you check the space?