Final answer:
Postoperative instructions following scleral buckling should include avoiding bending at the waist to prevent increased pressure on the eye that might disrupt healing.
Step-by-step explanation:
When teaching a client who is postoperative following a scleral buckling procedure for a detached retina, it's important to include specific instructions to ensure proper healing. The correct instruction among the options provided is: "Avoid bending at the waist." This is crucial as bending can increase pressure in the eye, which could potentially harm the repair site. Sleeping on the affected side could also cause undue pressure or harm, over-the-counter eye drops should not be used unless specified by the doctor, and it is usually advised to gradually resume normal activities rather than immediately, to prevent strain.