Neostigmine Beta blockers

Answer A. Mydriasis and fixed far vision can be due to either muscarinic receptor antagonists or ganglionic blockade. Because no M blockers are listed, the correct answer is mecamylamine. Alpha agonists (phenylephrine) have no effects on the focus of the eye. The cholinesterase inhibitor (neostigmine) and alpha blocker (phentolamine) cause miosis. Ocular effects of the beta blocker (timolol) are restricted to decreased formation of aqueous humor by the ciliary epithelium. 

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