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