The primary muscle used to squint is the orbicularis oculi.
The orbicularis oculi muscle is crucial for various eye actions and facial expressions. Here's a breakdown:
- Primary Function: Its main job is to close the eyelids.
- Squinting: The reference text specifically mentions that the orbicularis oculi is involved in squinting.
- Other Functions: Besides squinting, it also helps with frowning and other eye closures.
In essence, when you squint, you're primarily engaging your orbicularis oculi muscle to partially close your eyelids.
