 Astigmatism is the optical term for more than one point of focus. It occurs when the surface of the cornea or crystalline lens is not spherical. |  What is Blepharitis? Blepharitis is the inflammation of the eyelids. There are two types: Anterior blepharitis - this affects the area of the eyelids where the eyelashes sit. Posterior blepharitis - this affects the meibomian glands which produce part of the tears. Blepharitis is common and GPs say it accounts for 5% of all eye problems they see. |
 A cataract is a clouding of the lens in your eye and can develop in one or both eyes. The lens is normally clear and sits behind the iris � the colored part of the eye. |  Conjunctivitis is an inflammation of the conjunctiva. The conjunctiva is the thin layer that covers the white of the eye and the inside of the eyelids. It can affect one or both eyes, causing discomfort |
 Diabetes can lead to a condition called Diabetic Retinopathy as well as other eye problems. Diabetic retinopathy (damage to the retina) is caused by complications of diabetes mellitus, which can eventually lead to blindness. |  Dry eye is a common medical condition and is caused by a problem with the drainage, evaporation or production of tears. Tears are moved across the eye when you blink to lubricate the front surface of your eye, wash away debris, protect against infection and to help stabilize vision. |
 What are flashes and floaters? The eye is filled with a clear, jelly-like substance called the vitreous humour that helps maintain the eye's shape. Debris within the vitreous humour casts a shadow on the retina at the back of the eye, and appears to 'float' in your field of vision. |  Glaucoma is the name given to a group of eye conditions where the optic nerve is damaged at the point where it leaves the eye. The optic nerve carries images from the retina, the light sensitive membrane attached to the inner surface of the eye, to the brain. |
 The retina is the light sensitive membrane attached to the inner surface of the eye. Light enters the eye and falls on the retina allowing us to see images, these are transmitted along the optic nerve to the brain where they are processed so we can see. |  Myopia is the term used to define short sightedness. Light from a distant object forms an image before it reaches the retina. This could be because the eye is too long, or the cornea or crystalline lens is too strong. |
 Presbyopia describes the condition where the eye exhibits a progressively diminished ability to focus on near objects. It is a perfectly natural condition that eventually affects everyone but because the effects are gradual, you may not notice that anything is wrong with your eyesight initially. |  Retinoblastoma is a rare form of eye cancer which generally affects children under 5 years old. It is treatable but if signs are noticed they must be checked out quickly. |