1. Depth Perception

2. Depth perception, Size & Distance of objects
Depth perception, size of objects, and distance are ascertained through:
- Monocular and
- Binocular cues.

3. Determination of the distance
3 methods for the determination of the distance of the objects from the eyes
Size of image of known objects
Phenomenon of moving parallax
Phenomenon of stereopsis

4. Size of image of known objects
Image of the far objects is smaller than the nearer objects
Brain knows the size of the image of known object when they are near and change in size when the same
objects is far away
Brain automatically
calculates the distance
from this

5. Phenomenon of moving parallax
Image of the nearer objects moves more across the retina, with the movement of the eye
Very near objects are out of field of vision with small movement of eyes or head
Far objects image remains on the retina even with tremendous movement of the eye or head
From this phenomenon brain estimates the relative distances of the objects

6. Moving Parallex- Note:Distant objects moves slowly than Nearer Objects

8. Phenomenon of stereopsis
Binocular vision
Object very near to the eyes forms images on the temporal side of the retinae
As the object moves away from the eyes the two images in the two eyes come more towards the nasal sides of the retinae
Nearer objects have more un-fused points of the two images than the far objects
From these two phenomenon of binocular vision brain can estimate the distance of the objects

9. Distance perception by size and stereopsis

10. Geometric Basis of Steropsis
When a person stares at an object, the two eyes converge so that the object appears at the center of the retina (corresponding points) in both eyes.
Other objects around the main object of interest appear shifted in relation to the main object