Parks Three Step tool

  • Superior Rectus (RSR)
  • Superior Oblique (RSO)
  • Inferior Oblique (RIO)
  • Inferior Rectus (RIR)
  • Superior Rectus (LSR)
  • Superior Oblique (LSO)
  • Inferior Oblique (LIO)
  • Inferior Rectus (LIR)

Left Hyper Right Hyper Which eye is hyper deviated in primary gaze?

Left Gaze Right Gaze Is the vertical deviation greater in right gaze or left gaze?

Left Tilt Right Tilt Is the vertical deviation greater with right head tilt or left head tilt?

The Parks Three Step test (also know as Parks-Bielschowsky Three Step Test as well as the Parks-Helveston 3 step test) is used to isolate a paretic extraocular muscle in acquired vertical diplopia or double vision. It is not effective for use in assessing horizontal diplopia and it is not reliable in patients with prior strabismus surgery. The test is more reliable with recent onset diplopia. Because of the spread of concomitance, eventually the muscle actions that the test relies on become more difficult to isolate. By calculating the vertical deviation in primary gaze, left and right gaze, and right and left head tilt, the Park's Three Step Test is able to eliminate each muscle's primary field of action. Eventually the affected muscle will be the only one remaining.

Empire New York
Calvin Klein

Practice Location

Logan City Centre
Cnr Wembley and Kingston Roads
Logan Central, Qld 4114

Ph: 07 3299 3699
Fax: 07 3290 4558
Email: via our contact page

Operating Hours

Monday 8:30am - 5:00pm
Tuesday 8:30am - 5:00pm
Wednesday 8:30am - 5:00pm
Thursday 8:30am - 7:00pm
Friday 8:30am - 5:00pm
Saturday 8:30am - 12:00pm
Sunday Closed