Vision

Questions and Answers

Why can't we process everything in high resolution?

This would cause the blind spot to take up most of the retina

Why do we see grey dots when we look at an intersection of the Hermann Grid?

On centre of receptive field located at that intersection has more light in its inhibitory surround than any other receptive field. This is lead to lateral inhibition.

Which one of these features about the retinal ganglion cells is incorrect?

Retinal ganglion cells respond to light falling outside the receptive field

Cells do not respond to stimulus bigger than it's receptive field. Instead a change in light within the receptive field causes a response.

True Signup and view all the answers

What is the role of the cornea?

It is a transparent window in which it helps focus light onto the retina. Signup and view all the answers

What is the vitrenous humour?

It is a gelatinous subtance in the main cavity of the eye. It keeps the eyeball in shape and keeps the retina at the back of the eye. Signup and view all the answers

How can a person with emmetropia see close objects?

Ciliary muscle contracts lead to relaxation of the zonules, lens get fatter, refractive power increases. Signup and view all the answers

Which feature of rods is incorrect?

Rods are most sensitive to blue light. Signup and view all the answers

The blind spot is area of the retina where there are no photoreceptors. It is 12 - 15 degrees into the nasal retina where the ganglion cells axon and blood vessels leave the eye.

True Signup and view all the answers

Which feature is correct about the retinal ganglion cells?

It contains magnocellular (carries info about dynamic aspects of the world) and parvocellular (carries info about colour). Signup and view all the answers

Study Notes

Visual Perception

We can't process everything in high resolution because of limitations in the visual system.

Hermann Grid

Grey dots appear at the intersection of the Hermann Grid due to an optical illusion.

Retinal Ganglion Cells

A correct feature of retinal ganglion cells is that they respond to changes in light within their receptive field, not to stimuli larger than it.
An incorrect feature of retinal ganglion cells is that they respond to stimuli bigger than their receptive field.

Eye Anatomy

The cornea's role is to focus light onto the retina.
The vitreous humour is a clear gel-like substance that fills the space between the lens and the retina.

Visual Acuity

A person with emmetropia (normal vision) can see close objects by increasing the curvature of the lens and reducing the focal length.

Rods

An incorrect feature of rods is that they have some other characteristic (not specified).

Blind Spot

The blind spot is an area of the retina, 12-15 degrees into the nasal retina, where there are no photoreceptors and the ganglion cells' axons and blood vessels leave the eye.