Correlation between depth perception by three-rods test and stereoacuity by distance Randot Stereotest

Area of Science:

• Ophthalmology
• Optometry
• Vision Science

Background:

• The Road Traffic Act in Japan mandates depth perception and visual acuity tests for taxi and truck drivers.
• The three-rods test is used to assess depth perception for driving licenses.

Purpose of the Study:

• To investigate the correlation between the three-rods test and established static stereopsis tests.
• To validate the three-rods test as a measure of depth perception relevant to ophthalmic practice.

Main Methods:

• 54 healthy subjects (18-25 years) with normal visual acuity and no strabismus participated.
• Stereopsis was measured using TNO Stereotest, Titmus Stereotest (near), and Distance Randot Stereotest (distance).
• The three-rods test involved aligning a moving central rod with two fixed rods; erred distance was recorded.

Main Results:

• A positive correlation was found between the three-rods test erred distance and distance stereoacuity (Distance Randot Stereotest, ρ=0.418, p=0.0023).
• The three-rods test also correlated with near stereopsis tests (TNO, Titmus).
• TNO and Titmus Stereotest results showed a positive correlation with each other (ρ=0.431, p=0.0017).

Conclusions:

• The three-rods test demonstrates consistent results with distant static stereoacuity measurements.
• The test effectively assesses depth perception and eye-hand coordination.
• Findings support the utility of the three-rods test in clinical settings and for driving assessments.