All patients underwent full ophthalmologic and orthoptic examination. The colored Doppler USG to bilateral carotid arterial system was applied to first 12 patients after their head positions were corrected. To the second 12 patients, the colored Doppler USG to bilateral carotid arterial system was applied with head position caused by IVth nerve paralysis in addition to the same investigation made with first 12 patients. The results of investigation with corrected head position are grouped under Group A (n 24 patients) and the results of investigation with uncorrected head position are grouped under Group B (n 12 patients). The colored Doppler studies were done in a private diagnosis center with 6-10 mHz linear and in the cases where position is necessitated with 5-7 mHz endokavier prob and Toshiba (Eccosee) colored Doppler apparatus was used. All measurements were taken by the same radiology doctor.