welcome to this first in the series of guided meditation with srp asmr. for today's episode
we're going to think about the human eye its features structures anteriorly internally and
externally. so first things first just ensure you are lying down in the supine position
the eyes are closed and you're just breathing naturally.
so let's think about the human right eye your right eye probably going to start anteriorly
i'm not going to think about the lids and lashes today but just the
globe itsel.f so at the front we're going to think about the transparent
window to the eye if you like and it's understood there are five layers
to this window of the eye known medically as the cornea so thinking about the layers
the most external layer the one in contact with the atmosphere is the epithelium then
we go to the thin Bowman's membrane the middle and thickest layer is the stroma
and then we have Descemet's membrane and then the final and the fifth layer
is the corneal endothelium this is the layer in contact with the aqueous humour,
but we'll come to this a little bit later so bring your way back to the front surface of the cornea
if we move to the left as we're facing your eye notice that we have an ocular muscle there known
as the lateral rectus on the opposite side the opposing ocular muscle there is the medial rectus
12 o'clock top of the eye the superior rectus, six o'clock is the inferior rectus,
located nearby is the inferior oblique and then back to the top it's working its way under the
superior rectus is the superior oblique ocular muscle, so that's six extra ocular muscles
attached to the eye to allow up and down left right, diagonal and rotational ocular movements
now we're considering the white of the eye, this is known as the sclera
this is the outer tunic of the eye the eye is formed of three tunics
so the sclera gives the eye shape and strength and i'm thinking about the visible area if i'm
facing you directly i want to think about the thin conjunctival membrane the thin conjunctival
membrane where you will find things such as goblet cells the mast cells and covering the cornea and
the conjunctiva would be the tear film which has immunological properties, keeps your eye hydrated,
it washes away any debris that can then exit through the tear ducts upper and lower puncta
so that is a little bit about the more external areas of the eye,
obviously if we just switch to the back of the eye if we rotate your right eye
welcome to the optic nerve, the optic nerve is cranial nerve number two
the central retinal artery and the central retinal vain we have some vessels piercing the back of the
optic nerve the posterior ciliary arteries and you may see some veins traveling behind the eye
piercing forming the vortex veins that we can visualize
when performing ophthalmoscopy of the eye, we might see the vortex veins in the peripheral zones
it doesn't matter whether you are thinking about whether the eye is hyperopic, myopic
or astigmatic, it can just be any eye in the world so going back to the front of your right eye
and the area in front of the iris but behind the corneal endothelium
is the anterior chamber which is where you will find the aqueous humour
and then we talked about the iris there briefly, doesn't matter whether the iris is blue,
brown, hazel two tone or pigmented, it can be any iris you want it to be so the iris
is the part of the eye that controls how much light enters the eye,
we'll find the sphincter and the dilator muscles within the iris
so looking at the anterior portion of the iris you have your collarets
you have your crypts. as we said we might see some pigmentation of the iris and on the slit lamp we
may see some little vessels close to the anterior part of the iris best visualized on the slit lamp
the iris has a hole in the center this is known as the pupil
it doesn't matter whether the pupil is two millimeters or a very large dilated
eight millimeter pupil, it doesn't matter whether it's dilated or a miotic pupil,
it can be any size you want it to be
the space between the edge of the iris and the sclera is where the majority of aqueous humour
drains from the eye through the trabecular meshwork, that's the area running 360
to the edge of the iris the sclera in the anterior chamber is the trabecular work,
we have a nice little drainage system in the eye, a nice drainage system
so we're going to go through the pupil now and then we will hit
the anterior crystalline lens, the anterior surface the crystalline lens,,
then we will migrate to the edges of the crystalline lens
where we shall find the lens zonules attached in a 360 degree pattern
which are then attached to the ciliary body attached to the ciliary body
the ciliary body is a producer of aqueous humour that will travel past the posterior
iris and the anterior lens surface, through the pupil and into the anterior chamber
that will drain the majority, will drain through the trabecular meshwork
so the ciliary body forms part of the middle tunic of the eye, this tunic is a vascular layer
known as the choroid, it's known as the choroid
now if we are working our way through the
crystalline lens we're going to travel from the anterior to the posterior surface
through the other side and we're into the large hollow space of the eye, the dome. this is an area
you will find yourself in the vitreous humour, you are now in the vitreous humour of the eye
which normally, it has a nice framework it is pressed against the retina
very nicely and you will find hyaluronic acid in the jelly of the eye in the vitreous humour
okay with your right eye, imagine it's straight, i'm going to go straight through the pupil
the crystalline lens, dead straight,, and we shall hit the central vision part of the eye
this is known as the macula this is the macular region, your central
vision area picks up fine details and colours nice and sharply
it's concentrated mainly of cones, a specific type of photoreceptor
located in the retina, forming a part of the retina. the centre of the macula is the fovea
and then if this is your right eye, moving slightly to the right of the macula where
we shall find the head of the optic nerve approximately one to 1.2 million nerve fibers
all congregate to form the head the optic nerve. these nerve fibers carry the messages
all the way to the back of the brain, the visual cortex area, giving you the perception
that you require in order to see the world, so you actually see with your brain and not the eye
coming back to the head of the optic nerve this should be pink
and defined, might be some cupping on the optic nerve
and we will see the blood vessels on the surface and veins migrating out and draining the eye back
through the centre, through the central retinal vein
so now we've found the macula and the optic nerve we're going to just explore the peripheral retina
that's where we see lots of blood vessels and the vortex veins that we discussed earlier.
the retina should be clear, flat but there might be some normal findings of pigmentation
there may be some atrophic retinal holes
on the retina we do not want to see any tears, we don't want to see any detachments, we don't
want to see any haemorrhaging on the retina including that on the macula, the optic nerve,
we don't want to see any oedema at the macula either
so the retina wraps all around the back inner portion of the eye which capture the light signals
then convert it to chemical energy,
travel congregate the nerve fibres the optic nerve head and then travel off on their journey
so that's the end of the guided ocular meditation,
let's take a few moments to relax now keep the eyes closed