The Human Eye
The human eye or eyeball is the organ of sight. It is shaped like a slightly flattened sphere and the way it works is very complex, often compared to the workings of a camera.
How does it work?
The eye obtains information about its surroundings through lightsmall parts works in synergy with the others to visualise the world around us, transmitting messages to the brain, which is then able to interpret the various messages.
The light reaches the iris, which filters the intensity and helps the lens and the vitreous in the focusing process. This first process enables the retina to transform light into electrical signals, which are used to process images with the help of the optic nerve, the brain’s messenger.
Curious to know more about the anatomy of the eye?
Click on the + buttons to learn more
A stye is an inflammation of the eyelids that affects the sebaceous glands at the base of the eyelashes (Zeis glands)
Blepharitis is a fairly common inflammation of the eyelids (in Greek blépharon), located in the area where the eyelashes are rooted.
Ectropion is a condition in which the lower (rarely the upper) eyelid of one or both eyes is turned outwards.
Entropion is an eye condition in which the margin of the upper and/or lower eyelid is turned inwards.
Chalazion is a fairly common eye condition and usually appears as a small “bump” located on the upper or lower eyelid.
Hypermetropia, along with astigmatism and myopia, belongs to the group of ametropias (disorders relating to the refraction of the eye), i.e. it is a vision defect.
Dry eye syndrome is a multifactorial disease that affects the eye's surface, particularly the tear film
Bacterial conjunctivitis is an infectious conjunctivitis where the inflammation is caused by bacteria.
Allergic conjunctivitis occurs when the inflammation is caused by an immune reaction triggered by certain substances (allergens) in the environment
Keratitis is an eye disease characterised by an inflammatory process affecting the cornea, the transparent structure that forms the front of the eyeball.
Tear duct disorders
Of the various disorders that can affect the lacrimal apparatus of the eye, the most common is obstruction of the tear ducts.
Myopia is a very common vision defect that leads to blurred vision of images from a distance; in myopic patients, near vision can be good.
Presbyopia is a visual impairment consisting of the gradual and progressive loss of the ability to focus on the closest objects.
Astigmatism is a vision disorder that is mainly caused by an abnormality in the curvature of the cornea, the most anterior structure of the eyeball, which takes on a slightly more ovoid shape instead of a spherical one.
Ocular hypertension occurs when the internal pressure of the eye (or ocular tone) is consistently higher than levels that are defined as standard
Uveitis is an eye disease consisting of inflammation of the uvea, the middle layer of the eyeball wall that is rich in blood vessels.
Cataracts are a progressive eye disease that consists of the opacification of the crystalline lens, which is located between the iris and the vitreous body.
Posterior vitreous detachment
Posterior vitreous detachment is an ocular condition consisting of a “disconnection” between two sections of the eye, the retina and the vitreous humour.
Diabetic retinopathy is an eye disease that occurs as a fairly common complication of diabetes: it is estimated to affect about 1 in 3 people with diabetes.
Retinal oedema is the clinical manifestation of many eye diseases, and consists of an abnormal accumulation of fluid within the retina
Glaucoma is an opticopathy (i.e. a pathology of the optic nerve) associated with increased intraocular pressure.