An evaluation of stereoacuity (3D vision) in practising surgeons across a range of surgical specialities

Judging depth is important in surgery. Although there are several cues that permit depth perception, stereoacuity has been singled out as a possible predictor of surgical ability. However, it is not clear whether high-grade stereoacuity is necessary for a career in surgery. To help answer this, we aimed to evaluate stereoacuities in practising surgeons across a range of surgical specialities.

We recorded stereoacuity values on 66 surgeons working at a London teaching hospital using three standard stereotests: Titmus, TNO and Frisby. There were 36 Trainees and 30 Consultants, covering 12 surgical specialities.

Median stereoacuities (with range) for the whole group were: 40 s arc on Titmus (40-800), 30 s arc on TNO (15-480) and 20 s arc on Frisby (20-600). Four surgeons had no recordable stereoacuity on TNO, and one was also unrecordable on Titmus. Three of these four were Consultants. Depending on the test used, high-grade stereopsis was found in 74%-83% of surgeons while reduced stereopsis was found in 2%-14% of surgeons.

While we found that most surgeons in current NHS practice have high-grade stereoacuity, there are also surgeons with reduced stereopsis and some with no stereopsis. The findings do not therefore support the assertion that high-grade stereopsis is a universal requirement for a career in surgery. It would be difficult to justify setting a stereoacuity criterion for entrance into a surgical training programme.