the drug is an anticholinergic - in the eye the ciliary muscle...

the drug is an anticholinergic - in the eye the ciliary muscle is responsible for adjusting lens shape to accommodate focal points. Acetylcholine is a transmitter that enables the ciliary muscle movement. Anticholinergics block acetylcholine which impacts on the muscle, in turn this affects the eyes ability to accommodate to varying focal points so the lens doesnt adjust. The result is out of focus vision. The eye drains fluid at an angle adjacent to the ciliary muscle - this drainage angle can reduce with anticholinergics, so the eye is not draining fluid as per usual, glaucoma is an increase in eye pressure so if drainage is reduced, there is a risk the pressure inside the eye can increase.