Checkout this video:
How does light travel?
Most people think that light travels in straight line You might be surprised to learn that this isn’t always the case! In fact, light can travel in different ways depending on what it’s bouncing off of.
Let’s start with an example everyone is familiar with: a mirror. When you look in a mirror, you see an image of yourself because the light reflecting off of your body is being sent back in a straight line directly into your eye. But what about when you look at something that isn’t a mirror, like a piece of paper? In this case, the light is still bouncing off of the object and into your eye, but it’s not bouncing back in a perfectly straight line. Instead, the light hits the surface of the paper and scatters in all different directions before reaching your eye. This is why you can see things that aren’t directly in front of you when you look at a piece of paper – some of the light has bounced off to the side and into your eye!
There are other ways that light can travel too. If you’ve ever seen a rainbow, you know that light can bend! When sunlight passes through water droplets in the air, it slows down and bends as it enters each droplet. Once it exits the droplet, it speed up and bends again. This bending cause the different colors that make up sunlight to separate so that we can see them as different colors when they reach our eyes.
As you can see, there are lots of different ways that light can travel depending on what it hits along the way!
What is light?
Most people think of light as coming from the sun or a light bulb. But what is light?
Light is a type of energy that travels through the air and is used to see things. It is made up of tiny particles called photons.
Light travel to the eye in a straight line. When it hits an object, some of the light will bounce off the object and into your eye. This is how you are able to see things.
How light travel to the eye?
Light waves are electromagnetic waves that travel through the vacuum of space at the speed of light. These waves are created by the vibration of electrically charged particles.
Light waves are classified according to their wavelength. The human eye can detect light waves in the visible spectrum, which includes wavelengths from 400 to 700 nanometers. This visible spectrum is often referred to as “visible light.”
When light waves enter the eye, they pass through the cornea (the clear, curved layer at the front of the eye). The cornea bends (or refracts) the incoming light rays and directs them toward the pupil (the black circle in the center of the eye). The pupil controls how much light enters the eye by widening or narrowing in response to the level of illumination.
After passing through the pupil, light rays pass through the lens. The lens further refracts these rays and focuses them onto what’s called the retina — a thin layer of light-sensitive cells at the back of the eye.
The retina converts these focused light rays into electrical impulses. These electrical impulses travel along optic nerves to reach different areas of our brain. Once arriving in our brains, these electrical impulses are turned into images that we see.
What is the eye?
The eye is the organ of sight, a nearly spherical hollow structure about 2.5 cm in diameter that is lined with three coats of vascular and nerve tissue. Its outermost coat, the fibrous tunic, is composed largely of collagen and other structural proteins and provides support and protection. The middle coat, the vascular tunic or choroid, consists primarily of smooth muscle fibers, blood vessels, andconnective tissue. The innermost layer of the eye, which lines the back half of the eyeball, is a thin membrane called the retina. Sensory receptors for vision (rods and cones) are concentrated in an area known as the fovea centralis, which is located in the center of the retina just behind its opening (the pupil). In front of the retina is a clear jellylike substance called vitreous humour that fills most of the eyeball cavity; it helps to maintain intraocular pressure and provides support for some of the eye’s internal structures.
How do we see?
There are three main ways that light can travel to the eye:
-Reflection: This is when light bounces off of an object and into your eye. For example, when you see your reflection in a mirror, the light has reflected off of your body and into your eye.
-Transmission: This is when light passes through an object and into your eye. For example, when you look through a window, the light from outside passes through the glass and into your eye.
-Absorption: This is when light is absorbed by an object and does not reach your eye. For example, if you are looking at a black object, the light is being absorbed by the object and you cannot see it.
What is the cornea?
The eye has several parts that work together to allow us to see. These parts are the cornea, pupil, iris, lens, retina, choroid and Optic Nerve.
The cornea is a dome-shaped clear tissue that covers the front of the eye. It plays a very important role in focusing light.
The pupil is the black part of the eye that controls how much light enters the eye. The iris is the colored part of the eye that surrounds the pupil. The lens is a clear part of the eye that helps to focus light on the retina.
The retina is a layer of tissue at the back of the eye that contains photoreceptor cells. These cells change light into electrical impulses that are sent to the brain. The choroid is a dark pigment layer between the retina and sclera that helps reduce reflections inside the eye.
The Optic Nerve carries electrical impulses from the retina to the brain where they are turned into images.
What is the pupil?
The pupil is the black opening in the center of your eye that regulates how much light enters your eye. It does this by getting bigger or smaller. When it’s bright out, your pupil gets smaller to protect your eye from too much light. When it’s dark, your pupil gets bigger so that more light can enter your eye and you can see better.
What is the lens?
The lens is a clear part of the eye that helps to focus light, or an image. Muscles attached to the lens help it to change shape so that it can focus on objects at different distances. The cornea is the clear front surface of the eye. It also helps to focus light and provides much of the eye’s optical power. Together, the cornea and lens bend (refract) incoming light rays so that they focus precisely on the retina — the sensitive inner lining of the back of your eye.
What is the retina?
The retina is the layer of tissue at the back of the eye that is sensitive to light. It is made up of many small parts, including rods and cones. These are special cells that aresensitive to different parts of the light spectrum. When light hits the retina, it triggers a chemical reaction that sends signals to the brain. The brain then interprets these signals as images.
How light travel through the eye?
There are numerous ways in which light can travel to the eye, but the most common is through the use of lenses. Lenses are curved pieces of glass or transparent material that focus light rays onto the retina, which is the light-sensitive layer of tissue at the back of the eye. The retina converts the light into electrical impulses that are then sent to the brain, where they are interpreted as images.