Ophthalmology True for diurnal variation of intraocular pressure (IOP) is A IOP is usually low in the morning hours B IOP is usually higher in the morning hours C IOP variation is related to plasma acetylcholine level D In normal eye lOP fluctuation is <10 mm of Hg. 💡 Explanation True for diurnal variation of intraocular pressure (IOP) is ✓ Correct Answer: B. IOP is usually higher in the morning hours