The Human Eye 2

An elongated eyeball or abnormal curvature of the cornea.

The clouding of the eye's clear lens, preventing light from reaching the retina.

Radial muscles relax, circular muscles contract, and the pupil constricts.

Aqueous humor.

Pain receptors in the conjunctiva stimulated by dust and foreign particles.

Light, sound, temperature, pressure, pain, and chemicals (taste and smell).

The ciliary muscles are relaxed, allowing the ciliary body to move further away from the lens.

By glasses with concave lenses or laser surgery.

They diverge light rays before they enter the eye to focus on the retina.

The pupil constricts to allow less light to enter and prevent damage to the retina.

It becomes more opaque, decreasing visual clarity and sharpness.

The anterior chamber (between the cornea and iris) and the posterior chamber (between the iris and lens).

Six eye muscles.

The process during which the eye adapts for the observation of nearby objects by changing the shape of the lens.

The choroid, the ciliary body, and the iris.

To conduct nerve impulses to the cerebral cortex of the brain where they are interpreted, resulting in the sensation of sight.

To regulate the amount of light entering the eye by controlling the size of the pupil.

The outer fibrous layer, the middle vascular layer, and the inner light-sensitive layer.

A strong, white, inelastic layer of connective tissue that forms the outer layer of the eyeball.

It serves as a point of attachment for the eye muscles and helps regulate the amount of light that passes through.

Nerve impulses.

It provides a wider field of vision and creates a perception of depth.

Nerve fibers from photoreceptors (rods and cones) synapse with sensory neurons, which then synapse with optic neurons to form the optic nerve.

To contract and relax to change the curvature of the lens during accommodation.

The anterior cavity and the posterior cavity.

Radial muscles contract, circular muscles relax, and the pupil dilates.

To absorb light rays and prevent internal reflection within the eye.

It widens and constricts to regulate the amount of light entering the eye.

Stereoscopic vision.

A reflex action that responds automatically to the amount of light entering the eye.

A condition where distant objects are seen clearly, but nearby objects are out of focus.

A thin mucous membrane known as the conjunctiva.

Maintains the shape of the eyeball, holds the retina in position against the choroid, and refracts light rays to form a sharp image.

The cornea, aqueous humour, and vitreous humour.

Vision with both eyes.

A concentration of receptors with the same function.

By glasses with convex lenses or laser surgery.

Ciliary muscles are relaxed, suspensory ligaments are taut, and the lens is flatter.

Behind the retina.

To secrete antiseptic tears that protect the conjunctiva from bacteria and dehydration.

In front of the retina.

Headaches, tiredness, and squinting.

The pupil dilates to allow as much light as possible to reach the retina.

Glasses, stronger non-reflective sunglasses, or a magnifying glass.

It forms the clearest and most accurate vision.

To allow light rays to pass through and to cause the refraction of incoming light rays.

Rods and cones.

The sensation of sight.

Ms. C.R. Els.

Receptors that detect light stimuli, concentrated in the eye.

It converges light rays before they enter the eye to focus on the retina.

An irregularly shaped cornea or lens.

To absorb excess light rays and prevent internal reflection.

A shortened eyeball or an abnormally flat cornea.

To detect light stimuli in high light intensity and provide color vision.

The lens, cornea, and vitreous humor.

Along the optic nerve to the cerebral cortex of the brain.

To detect stimuli and convert them into nerve impulses.

A condition where nearby objects are seen clearly, but distant objects are out of focus.

The lens becomes more convex (bulges out more) to increase refraction of light rays.

It has a rugby ball shape instead of a soccer ball shape.

A place where the optic nerve leaves the eyeball, which has no rods or cones, resulting in no image formation when light rays fall on it.

The pigment layer and the nervous tissue layer.

Removal of the lens and replacement with a clear synthetic lens.

To detect light stimuli in low light intensity and provide black and white vision.

On the yellow spot of the retina.

Smaller, inverted, and reversed.

By combining the two images to form a single 3-dimensional image.

Vitreous humor, which is jelly-like.

It changes shape to refract light rays from near and far objects to form a clear image on the retina.

To detect light and enable vision.

Receptors, the human eye structure, functioning of the human eye, visual defects.

In the bony eye sockets at the front of the skull.

To provide sight or vision.

The eyelids and eyelashes.

More or less spherical.