This is observational study. The investigator will measure optic nerve sheath diameter by ultrasound on the eye after cesarean section under spinal anesthesia.

Inclusion Criteria:

• Patients undergoing cesarean section under spinal anesthesia

Exclusion Criteria:

• Patients who did not agree to participate in the study
• Patients has ophthalmic diseases
• Patients has previous history of ophthalmic surgery.
• Patients has neurological disorders.
• Patients has history of head surgery.

Patients undergoing cesarean section under spinal anesthesia.