Cartrol is part of the Beta Blockers class and treats Glaucoma and Hypertension. Beta blockers are used to treat hypertension, angina, migraines, atrial fibrillation, essential tremor, heart attack, heart failure, ventricular arrhythmia, and glaucoma. They work by blocking certain receptors to reduce heart rate, dilating blood vessels for better blood flow, and reducing excess eye fluid to decrease eye pressure. Cartrol is only available as a brand name drug.