Common eye conditions - eye disease

A list of the most commonly diagnosed and treated eye conditions

This guide is one of two describing common eye conditions. They both explain what these conditions are and how optometrists can help. 

This guide covers eye disease: both minor eye conditions and sight-threatening disease. The Common eye conditions – refractive error guide covers refractive error – the reason that people need corrective lenses (glasses or contact lenses).

If an optometrist detects one of the sight threatening conditions described below, they will refer to an ophthalmologist as a matter of urgency. Minor eye conditions can be diagnosed and treated by optometrists. However in some cases an optometrist will refer a more minor condition to an ophthalmologist, particularly if the case is severe.

Sight threatening conditions 

Glaucoma represents a number of eye conditions where the optic nerve at the back of the eye is damaged. It is often asymptomatic and is linked to raised pressure within the eye.

When the nerve is damaged, it starts to cause problems with peripheral vision and, if left untreated, can cause permanent damage.

Diabetic retinopathy
This is a diabetic complication caused by damage to the blood vessels in the retina. If left untreated it can lead to permanent blindness.

There is a national eye screening programme in place within the UK, in which photographs of a patient’s retina are sent to an expert to detect signs of retinopathy and graded accordingly. Retinopathy can also be identified during the process of a routine sight test.

A cataract happens when either all or part of the lens in the eye becomes cloudy. There are different types of cataract, but the most common is age-related cataract.

Cataracts are very common, being the main cause of impaired vision in the world. If left untreated they can lead to partial or total sight loss.

Cataracts are very easily diagnosed by optometrists.

Age-related macular degeneration
Age-related macular degeneration (AMD) affects the central part of the vision and is caused by damage to the macular region of the eye, which is the part of the retina that provides high-resolution, central vision.

There are two main types of AMD – dry and wet. AMD is the most common cause of sight-impairment in the UK affecting older people.1

Retinal detachment 
Retinal detachment is a serious condition of the eye when the retina begins to pull away from the layer beneath which replenishes the retina with oxygen and nutrients.

If left untreated it can cause partial or total blindness.

An optometrist can investigate signs of flashes and floaters and refer to an ophthalmologist as a matter of urgency.

Minor eye conditions 

Dry eye (keratoconjunctivitus sicca)
Dry eye syndrome is a common condition that occurs when the eyes do not produce enough tears or they evaporate too quickly.

Dry eye can lead to the eye becoming red, swollen and irritated, and in certain cases cause considerable discomfort for the sufferer. In very rare cases dry eye can be a sight-threatening condition.

Red eye
Red eye comprises a number of conditions such as conjunctivitis or burst blood vessels in the eye and are usually nothing to be unduly concerned about. However, if the eye is painful this could be a sign of something more serious such as iritis (inflammation) or acute glaucoma.

While the majority of red eye conditions are short-term issues, it could be a symptom of other more serious conditions, such as acute glaucoma which is medically urgent and could result in loss of sight in that eye.

Watery eye (epiphora)
Watery eye is a condition that is usually caused by tears not draining correctly from the eye, or, paradoxically, as a result of an underlying dry eye condition which results in irritation. 

This can cause blurred vision, sore eyelids, swelling and vision impairment. Severe cases of watery eye can cause significant discomfort for sufferers.


Thomas Pocklington Trust (2006) Prevalence, causes and impact on sight loss in older people in Britain. content/uploads/2016/02/Prevelance-paper.pdf

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