The role of cholinergic signaling in myopia regulation is complex, as evidenced by: Clinically validated muscarinic antagonists (e.g., atropine) and nicotinic agonists (though primarily demonstrated in chick models) inhibit experimental myopia in animal studies, butα7-nAChR agonists are only effective in chick models, with no human data available. This evidence concerns the gene CHRNA4 and myopia.