Background: the cornea exhibits viscoelastic properties, which give it the quality of hysteresis. Corneal hysteresis is an important indicator of the biomechanical properties of the cornea. Objective: this study aimed to show the impact of diabetes on corneal biomechanics and to compare corneal biomechanics in diabetic to that in healthy non diabetic individuals using ocular response analyzer (ORA). Patients and Methods: we conducted our study on the diabetic patients and healthy non diabetic individuals to detect the relation between diabetes mellitus and the corneal biomechanics. Our study was performed on 120 eyes of 60 individuals as we categorized them into three groups. Group A involved 40 eyes from 20 controlled diabetic patients, group B involved 40 eyes from 20 non-controlled diabetic patients and 40 eyes from 20 healthy non diabetic individuals (Group C). Results: our study reported that diabetes mellitus led to an increase in corneal biomechanics as CH and CRF were elevated in patients with diabetes mellitus (Groups A & B). Conclusion: the corneal biomechanics in the diabetic groups were significantly higher compared to those of the control group, as the mean CH was 9.23 ± 0.98 mmHg in the controlled diabetic group (Group A), 10.11 ± 0.44 mmHg in the noncontrolled diabetic group (Group B) and is 8.03 ± 0.94 mmHg in the healthy non-diabetic individuals (Group C). The difference in CH between the three groups was statistically highly significant (P = 0.00). Meanwhile, the mean CRF was 9.26 ± 1.35 mmHg in the controlled diabetic group (Group A), 10.03 ± 0.99 mmHg in the non-controlled diabetic group (Group B) and 8.37 ± 0.56 mmHg in the healthy non-diabetic individuals (Group C). The difference in CRF between the three groups was statistically highly significant (P=0.00).