Carteolol HCl is primarily used in the treatment of glaucoma and ocular hypertension. It functions as a beta-adrenergic blocker, reducing intraocular pressure by decreasing the production of aqueous humor in the eye. This helps to prevent damage to the optic nerve and preserve vision. It is typically administered as an ophthalmic solution, applied directly to the eyes. The medication is effective for long-term management of these conditions and is often prescribed when other treatments are not suitable or effective. Patients using this medication should follow their healthcare provider's instructions carefully to achieve optimal results.