Visual System and Human Eye Structure

The pupil is the opening in the iris through which light enters the eye. Its size controls the amount of light reaching the retina.

The process by which the lens changes shape to focus light on the retina, adjusting for varying distances.

Muscles that adjust the shape of the lens to focus light.

The ability of the eye to detect the presence of a dimly lit object.

The ability to see details in an object.

Vision using two eyes, allowing for depth perception and accurate distance judgment.

Predators typically have eyes in the front of their heads for binocular vision, enhancing depth perception to hunt prey effectively.

Prey animals often have eyes on the sides of their heads for wide peripheral vision that aids in detecting predators from different angles in their surroundings allowing them for better vigilance.

Vision in bright light, using cones.

Vision in dim light, using rods.

The number of receptors (cones or rods) that connect to a single retinal ganglion cell.

Neural pathways where cones signal to ganglion cells.

Neural pathways where rods signal to ganglion cells.

The central part of the retina, packed with cones.

Conversion of light energy into neural signals by photoreceptor cells.

Rapid eye movements between fixations.

In the dark, rods are depolarized and release glutamate.

In the light, rods are hyperpolarized and release less glutamate.

A light-sensitive protein in rods, that breaks down into retinal and opsin when exposed to light.

The pathway of visual information from the retina to the primary visual cortex.

The spatial arrangement of visual information in areas of visual processing in the brain, with similar locations in the visual field corresponding to similar locations in the brain.

The point where optic nerves from each eye partially cross over to the opposite side of the brain.

The area in the occipital lobe that receives and processes visual information from the lateral geniculate nucleus.

Primary visual cortex located in the occipital lobe.

The area of the visual field that, when stimulated, affects the firing rate of a neuron.

A visual neuron that fires most when light is shone in the center of its receptive field, and is inhibited when light shines in the surrounding area.

A visual neuron that fires most when light is shone in the surrounding area of its receptive field, and is inhibited when light shines in the center.

The visual cortex is a map of the retina.

The light-sensitive tissue lining the inner surface of the eye.

A relay station in the thalamus that receives and processes visual information from the retina.

Neurons in the primary visual cortex that respond best to bars or edges in a specific location and orientation.

These cells are more complex, they respond to straight lines of a specific orientation regardless of location within their receptive field.

The idea that a neuron's response to a stimulus can be influenced by the surrounding context, such as other stimuli or even the state of the brain.

Neurons in the retina that respond to various visual features like uniform illumination, orientation, motion, and direction of motion.

Neurons located in the thalamus that receive input from retinal ganglion cells and are sensitive to orientation, motion, and direction of motion.

A pathway in the brain that processes information about spatial location, movement, and motion. Often referred to as the 'where' pathway.

A pathway in the brain that processes information about object identity and recognition. Often referred to as the 'what' pathway.

The first area of the visual cortex in the occipital lobe that receives input from the thalamus, responsible for initial visual processing.

The area surrounding the primary visual cortex, receives input from the primary visual cortex and performs more complex visual processing.

The final stage of visual processing, it receives input from the secondary visual cortex and other sensory areas, allowing you to understand and interpret visual information.

Part of the visual association cortex responsible for recognizing objects and faces.

Part of the visual association cortex responsible for spatial processing and movement.

A neurological disorder where individuals lose the ability to recognize faces.

The difference in the images seen by each eye, caused by the eyes being slightly spaced apart. This difference helps perceive depth and judge distance.

The theory explaining that our visual system uses two types of photoreceptor cells, rods and cones, for different lighting conditions.

The number of photoreceptor cells (rods or cones) that connect to a single retinal ganglion cell. More convergence means greater sensitivity to light but less detailed vision.

The point on the retina where the optic nerve exits the eye, containing no photoreceptors, creating a blind spot.

The pupil is the opening in the iris that controls the amount of light entering the eye. It regulates the brightness of the image projected onto the retina.

Accommodation refers to the lens changing shape to focus light on the retina. This process is important for seeing objects at different distances.

Ciliary muscles are attached to the lens and control its shape. They contract and relax to change the lens' curvature, allowing for accommodation and focusing.

Sensitivity refers to the eye's ability to detect dim light. Acuity refers to the eye's ability to see details. Both are important for clear vision, but they sometimes act in opposition.

Predators have eyes in front, creating binocular vision for depth perception and judging distance. Prey have eyes on the sides for wide peripheral vision, allowing them to detect threats from a wider angle.

Light has two key properties: Wavelength, which determines color, and Intensity, which determines brightness.

Light enters through the pupil, then passes through the lens, and finally reaches the retina.

The pathway of visual information from the retina (where light is converted to signals) to the lateral geniculate nucleus (LGN) of the thalamus (a relay station) and finally to the primary visual cortex (V1) in the occipital lobe, where the signals are processed.

The area in the occipital lobe that receives and processes visual information from the lateral geniculate nucleus (LGN). It's responsible for initial visual processing, such as detecting edges, shapes, and movement.

A neurologically caused impairment in the perception of motion. Patients with akinetopsia see the world as a series of still frames.

The part of the retina closer to the nose, which sends information to the opposite side of the brain.

The part of the retina closer to the temple, which sends information to the same side of the brain.