Inclusion criteria:
patients aged 18–85 years old ASA class 1 & 2 scheduled for phacoemulsification cataract surgery
Exclusion criteria:
refusing, mentally challenged patients , history of chronic use of sedatives, narcotics or alcohol , allergy to any of the study medications , patients with severe chronic obstructive pulmonary disease, Asthma,, history of cardiac disease (cardiac block and bradycardia) bradycardia (heart rate less than 50 beats per minute), systolic blood pressure less than 90 mm, Severe hepatic failure, uncontrolled diabetes, left ventricular failure (EF less than 30), and cerebrovascular disease,severe renal failures