Color Doppler imaging allows for simultaneous two-dimensional anatomical imaging and Doppler evaluation of blood flow velocity.We examined 40 normal eyes (17 males and 23 females, aged 16 to 57 years) with this technique. The color Doppler unit used in this study had a 5.0-MHz PLF-503 ST phased-array scanning head. Each vessel examination was repeated 10 times during a single session.The following peak flow velocities were found: central retinal artery, 12.5 +/- 2.4 cm/s; central retinal vein, 4.4 +/- 0.49 cm/s; posterior ciliary arteries, 14.4 +/- 2.6 cm/s; vorticose veins, 5.5 +/- 1.0 cm/s; ophthamic artery, 36.9 +/- 7.0 cm/s. Ophthalmic artery systolic and end-diastolic velocities declined as a function of age; however, these changes were not significant (systolic: r = -0.24; diastolic, r = -0.22).This noninvasive technique allows quantitative assessment of blood flow velocity in these vessels.