ciliary muscle

https://doi.org/10.1351/goldbook.11681
Intrinsic smooth muscle of the eye that contracts to cause the lens to thicken, allowing accommodation to near vision.
Source:
PAC, 2015, 87, 841. (IUPAC Glossary of terms used in neurotoxicology (IUPAC Recommendations 2015)) on page 857 [Terms] [Paper]