What is the normal Hertel Exophthalmometry range for Caucasian adults?

• A. 10-20 mm
• B. 12-22 mm
• C. 8-16 mm
• D. 14-24 mm

Answer: (B)

Normal Hertel exophthalmometry distance for Caucasian adults is about 12–22 millimeters. The exophthalmometer measures how far the front of the eyeball projects from the lateral orbital rim, and this range reflects typical orbital anatomy in this population. Small differences between the two eyes can occur, usually within about 2 mm. Values above roughly 22 mm suggest exophthalmos or orbital disease, while values well below 12 mm are uncommon in adults. The other ranges don’t match the standard reference for Caucasian adults, which is why 12–22 mm is the best choice.