the human eye

the eye

Myopia

explain the condition

near-sightedness

eye is too long

eyes can not focus on distant objects; blurry objects in the distance

the cornea and eye lens refract the and brings the rays together in front of the retina

Solution

Diverging [concave] lens or surgery

HYPEROPIA

explain the condition

Far-sightedness

eyes cannot focus on nearby objects; blurry objects up close]

eye is too short

the cornea and eye lens refract the light and bring the rays together behind the retina

Solution

Converging [convex] lens or surgery

Presbyopia

explain the condition

may happen when we get older

eyes become too stiff and the ciliary muscles can no longer make the lenses change shape

solution

eyeglasses , contact lenses,

Astigmatism

explain the condition

blurred or distorted vision

cause by incorrectly shaped cornea

oval cornea instead of round shape

solution

converging lens , diverging lens or surgery

define cornea

The clear, dome-shaped front surface of the eye.

define pupil

The opening in the center of the iris through which light enters.

define iris

Colored part of the eye that control the size of the pupil

Define retina

The light-sensitive inner lining at the back of the eye.

define the lens of the eye

The clear structure behind the iris that focuses light onto the retina.

ciliary muscle

These muscles change the shape of the lens to focus on objects at different distances.

define aqueous humor

A clear, watery fluid that fills the space between the cornea and iris.

Define vitreous humor

The clear, gel-like substance that fills the space between the lens and the retina.

Define sclera

white part of the eye

Define optic nerve

Carries electrical impulses from the retina to the brain.

Define blind spot

The area on the retina where the optic nerve exits; it contains no photoreceptors.

how is an image transmitted from the eye to the brain?

Light enters the eye and is focused by the cornea and lens onto the retina

list the optical phenomena on nature

rainbow, sun dogs, shimmering, apperenth depth, mirage

discuss the optical phenomena in nature

Rainbows: Caused by the reflection, refraction, and dispersion of light in water droplets.

PART 1 of sundogs

Sundogs: Also known as parhelia, these are bright spots that appear on either side of the sun.

part 2 of shimmering

Shimmering: This occurs when light passes through air of varying temperatures (and densities). As the light bends irregularly through the "pockets" of moving hot and cold air, objects behind it appear to distort or "shimmer."

part 3 for apperenth depth

An object underwater appears shallower than it actually is because light bends (refracts) as it moves from water into the air.

part 4 mirage

Caused by the refraction of light as it passes through layers of air with different temperatures (and therefore different densities).

list the application of lenses

eyeglasses, microscope, binoculars, telescope

discuss the application of lenses

Microscopes

Microscopes are essential tools for magnifying tiny objects that are invisible to the naked eye. They can use it for forensic science, to analyze trace evidence for crime scenes, fingerprints, fibers and gun powder residue

Eyeglases

correct vision by refracting light, so it focuses accurately on the retina ,shields eye from UV rays [sunglasses] , fixed near sightedness, farsightedness

Binoculars:

Essentially two small telescopes mounted side-by-side. They use lenses to magnify distant objects and usually contain prisms inside to flip the image right-side up so it doesn't appear inverted.

Telescopes

used to collect light and magnify distant objects, making them to appear brighter and closer . It can also be use for navigation , in the past they used to track the starts like Polaris to help sailors determine their location