Session 5 of 12
The anatomy of the eye?
Course: TSA-TGSI-1.5 | Length: 4:17 mins | Instructor: Dean Homicki
Transcript
In this session, we're going to learn about:
The Anatomy of the Eye?
How does the eye work?
Let's begin with:
Sclera: The Sclera is commonly referred to as the white of the eye. It is fibrous and provides support for the eyeball, helping it keep its shape.
Iris: This is the coloured portion of the eye. The iris is a muscle. It controls the size of the pupil and, therefore, the amount of light reaching the retina.
Cornea: This is a transparent, dome-like layer that covers the pupil, iris, and anterior chamber or fluid-filled area between the cornea and the iris. It is responsible for the majority of the eye's focusing power.
Pupil: This is the dark spot in the centre of the coloured part of the eye, which, in turn, is called the iris. The pupil expands and contracts in response to light, acting similarly to the aperture on a camera.
Ciliary muscle: This muscular ring is attached to the lens and, as it contracts or relaxes, it changes the shape of the lens.
Lens: Once light has travelled through the pupil, it reaches the lens, which is a transparent convex structure. The lens can change shape, helping the eye to focus light accurately onto the retina.
Retina: The retina is the innermost layer of the eye. It houses more than 120 million light-sensitive photoreceptor cells that detect light and convert it into electrical signals.
Macula: The macula is made up of 'Cones' which capture colours in normal light conditions and allow us to distinguish detail.
Optic nerve: This thick bundle of nerve fibres transmits signals from the retina to the brain. There are around 1 million thin, retinal fibres that carry light information from the retina to the brain.
Vitreous Body: Found in the back section of the eye, vitreous body is a thick and gel-like fluid. It makes up the majority of the eye's mass.
Conjunctiva: A thin, transparent membrane that covers most of the white of the eye, and the inside of the eyelids. It helps lubricate the eye and protect it from microbes that could cause various diseases.
Choroid: A layer of connective tissue between the retina and Sclera. It contains a high concentration of blood vessels. It is just 0.5 mm thick and contains light-absorbing pigment cells that help reduce reflections in the retina.
The eye and our visual system work hard every second we are awake. So, what is it like when our eyes and our visual system don't work? What does a person living with a vision-impairments, mild-vision loss or total blindness, actually experience?
In the next series of course modules, we explore what a vision-impaired person experiences with their orientation in the built environment.
I'm Dean Homicki and I look forward to joining you in the next Learning Session
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Sources
TSA-TGSI-1.5 - This staebl.academy course module has drawn information from the following sources:
Medical News Today - Source: http://www.medicalnewstoday.com/articles/320608.php
