Hello Benjamin.

What you have learnt in school is correct, I'm glad your teacher is doing such a good job in teaching you all. I'm sure you can be a great doctor in the future.

Firstly, let me tell you about the external structures of the eye:

-Cornea. It is a dome-shaped transparent layer continuous with the sclera. it is a specialised form of the conjunctiva which refracts light rays into the eye.

-Conjunctiva. It is a thransparent membrane covering the sclera and is continuous with the eylids. It will secrete mucus to keep the front of the eyeball moist.

-Iris. It is a circular sheet of muscles which consist both the radial and circular muscles. This is the part of the eye which gives your eye the colour.

-Pupil. It is a hole in the centre of the iris which allows light to enter the eye.

-Eyelids. it protects the cornea from mechanical damage and it will remain partly close to prevent excessive light from entering the eye and damage the light-sensitive tissues.

-Eyelashes. They shield the eye from dust particles.

-Tear gland. It helps to wash away dust particles and keep the cornea moist for oxygen to dissolve in. It also helps to lubricate the conjunctiva to reduce friction when eyelids move.

Next, let me tell you about the internal structures of the eye:

-Sclera. It is a tough, white outer covering of the eyeball that you see when you look into the mirror. It is continuous with the cornea and its function is to protect the eyeball from mechanical damage.

-Choroid. It is the middle layer of the eyeball between the sclera and retina which is pigmented black to prevent internal reflection of light. It contains blood vessels that bring oxygen and nutrients to the eyeball and remove metabolic waste products.

-Ciliary body. It is a thickened region at the front end of the choroid which contains ciliary muscles which controls the thickness of the lens.

-Lens. it is a transparent, circular and biconvex structure which is elastic and changes its shape or thickness in order to refract light onto the retina.

-Suspensory ligament. It is a tissue that is attached to the edge of the lens to the ciliary body.

-Aqueous chamber. It refers to the space between the lens and cornea which is filled with aqueous humour, a transparent, watery fluid which keeps the front of the eyeball firm and helps to refract light into the pupil.

-Vitreous chamber. It is the space behind the lens and it is filled with vitreous humour, a transparent, jelly-like substance which keeps the eyeball firm and helps to refract light onto the retina.

-Retina. This is the innermost layer of the eyeball. It is the light-sensitive layer on which images are formed. It contains light-sensitive cells/photoreceptors which consists of rods and cones.

-Yellow spot. It is a small, yellow depression in the retina directly nehind the lens where images are normally focused.

-Optic nerve. This is the nerve that transmits nerve impulses to the brain when photoreceptors are stimulated.

-Blind spot. It is the region where the optic nerve leaves the eye and it does not contain any rods or cones.

These are the internal and external structures of the eye. I hope these information will help you during your journey of learning Benjamin. Good luck! =)

-Dr Alexandra Yeo