There are two main types of stereopsis tests: contour stereopsis and random dot stereopsis. Contour stereopsis tests use 3D glasses to detect depth in images where the disparity varies from 400-100 to 800-40 seconds of arc. Random dot stereopsis tests like the Random Dot E test use polarized dot patterns to detect raised letters or shapes within the patterns. There are several popular stereopsis tests, including the Titmus stereotest, Random Dot E test, Frisby test, Lang test, TNO random dot test, and Bernell stereo reinder test, which measure stereopsis in seconds of arc and are used to detect conditions like amblyopia and strabismus.

1. by :
stereopsis and types of
D.S.PREM SAGAR
13IMMO05, 3rd sem
stereopsis tests

2. stereopsis:
• stereopsis is the ability to perceive depth and 3- d structure
obtained on the basis of visual information deriving from two
eyes by individual with normally developed binocular vision
• stereopsis is usually reserved for the impression of depth arising
from binocular disparity
• stereopsis is measured at near as part of clinical assessment of
patients disorders of ocular motility and strabismus
• stereopsis can be measured near and distance

3. • contour stereopsis :
• The patient uses 3-D glasses and asked to look at a picture
and determine whether the 3-D figure can be seen
• the amount of disparity in images vary such as 400-100 sec
of arc and 800-40 sec of arc
• random dot stereopsis :
• The ran dot stereotest is a vectorgraph random dot
stereotest .It is frequently used for detecting amblyopia
,strabismus
• random dot test can measure stereoacuity to 20 seconds
of arc

4. • stereopsis is measured in seconds of arc (1* =60 minutes of arc ;
• 1 minute = 60seconds of arc )
• lower the value the better the acuity
• there are two types of stereopsis they are :
• 1.contour stereopsis
2.random dot stereopsis

5. Types of stereopsis:
• there are 6 types of stereopsis tests :
• 1.The Titmus stereotest
2.The Bernell stereo reinder test
3.The random dot E test
4. TNO Random dot test
5.Frisby test
6.Lang test

6. The Titmus stereotest :
• It is a contour stereotest . it is performed at a distance of 40
cms
• The Titmus test consists of 3D polarid vectograph consists of
two plates in the form of booklet viewed through polaroid
spectacles they are present right angle to each other .
• they have pictures like fly , circles ,animals .

7. The Random dot E test :
• The Random dot E stereotest is a vectograph consists of
demonstration plate and two test plates
• The demonstrated plates contain a raised E that can be seen by
anyone who has good acuity
• each of the test plates is printed with a polarized random dot
pattern and requires the use of polarized glasses
• A patient who has stereopsis will see a raised letter E in the
random dot pattern of one of the test plates ,where the other
plate is blank

8. Frisby test:
• The Frisby test consists of three transparent plastic
plates of varying thickness.
• On the surface of each plate are printed four squares of
a small randomly distributed shapes
• one of the squares contain a hidden circle
• the test doesn't require special spectacles because the
disparity is created by thickness of plate .
• the disparity measured is 600to 15 seconds of arc

9. lang test :
• The Lang test can be used to asses stereopsis in very young
children and babies who may reach out to touch the pictures
• it doesn't require special spectacles
• the targets are seen by alternately by each eye through build in
cylindrical lens element.
• displacement of dot creates disparity and the patient is asked to
name or point to a simple shape such as star ,on the card
• the degree of disparity is quite gross ranging 1200 to 600 seconds
of arc at 40cms

10. TNO random dot test:
• it consists of seven plates of randomly distributed paired
red and green dots which are viewed with red and green
spectacles
• within each plate the dots of one color forming the target
shape .
• the disparites measurment ranges from 19,80 to 15
seconds of arc
• it is tested at a distance of 40cm

11. The Bernell stereo reinder test:
• The bernell stereo reinder test it resembles titmus stereotest
• it is a polarized test proving stimuli for both gross and fine
stereopsis testing
• the test has the advantage that the examiner can make the
reinder's nose wiggle by rotating the picture slighly