Glossary of the technical terms
The following page is here because we know that a lot of the terminology used
when diagnosing eye conditions can be very confusing.
Please select a letter below to find a definition for a word you are looking for...
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Adjustable sutures
Sometimes a better surgical outcome through squint surgery may be achieved by using adjustable stitches. The operation is performed under general anaesthetic and the stitches are tied in a bow at the end of the operation. You are then woken up and the eye position measured. If the eye position has not been altered enough we can make minor alterations in the eye position and then re-tie the stitch to secure it. This is done with local anaesthetic drops to numb the eye. This makes the operation more precise, especially, when there has already been previous surgery.
Amblyopia
The poor vision of one eye commonly caused by a squint, a need for glasses in childhood or something getting in the way of the vision of one eye (such as a cataract). This is what health professionals mean by a lazy eye. It is caused by the brain ignoring the vision from one eye. Treatment requires patching of the good eye so that the brain is made to use the lazy eye.
Anaesthetist
A doctor who specialises in giving general anaesthetics (puts people to sleep for their operation).
Analgesic
A drug which relieves pain.
Antibiotic
A drug used to treat bacterial infection
Astigmatism
Abnormality of the shape of the cornea (clear window on the front of the eye). Subtle changes in the curvature of the cornea (making it more like the shape of the back of a desert spoon than the back of a soup spoon) cause distortion of the vision. This can be corrected by giving glasses.
Anisometropia
This occurs when there is a difference in the refractive error of each eye. This results in blurred vision, especially in the eye with the greatest refractive error. In children, the wearing of glasses alone does not always correct the vision. A patch may be required, covering the good eye, to encourage the eye with the weaker vision to develop.
Bilateral
Both sides. A bilateral squint operation means that both eyes are operated on.
Conjunctiva
Membrane lining eyelid and the exposed surface of the eyeball.
Conjunctivitis
Inflammation of the conjunctiva. This causes a red eye. It can be due to trauma (including surgery), infection ("pink eye" caused by bacteria or viruses) or allergy (hayfever).
Convergent
A convergent squint is a mis-alignment of the eyes - with eyes turning in.
Convergence Insufficiency
A weakness of the eye muscles that are responsible for turning the eyes in to read.
Cornea
The clear window on the front of the eye.
Diplopia
Seeing double vision.
Double vision
The appreciation of two images of the same object some or all of the time. The two images may be vertically separated (one on top of the other) or horizontally separated (side by side) or both (oblique).
Divergent
A divergent squint is a mis-alignment of the eyes with the eyes turning out.
Esotropia
Another word for convergent squint.
Exotropia
Another word for divergent squint.
Hypermetropia
Long sighted. Difficulty focusing for near but also blurred vision for distance if very long sighted. This is the most common cause of convergent squint (eyes turning in).
Iris
The coloured part of the eye surrounding the pupil.
Short sighted. Blurred vision for distance. Near vision is usually good. Tends to start in adolescence but can be the cause of poor vision in childhood.
Nil by mouth
The term used for the period of time (usually 4 or 6 hours) before an operation during which NO food or drink must be taken. This must be strictly adhered to for safety under anaesthetic.
Nystagmus
An uncontrolled movement of the eyes, usually from side to side, but sometimes the eyes swing up and down or even in a circular movement.
Occlusion
See patching.
Optometrist
A professional specialised in the assessment of refractive errors (the need for glasses).
Orthoptic Exercises
A programme of eye exercises that aim to improve the muscle weakness associated with convergence insufficiency and therefore eliminate the symptoms of blurred vision, eyestrain and headaches. The exercises are carried out at home and involve commitment and motivation on the patient’s part.
Orthoptist
A professional specialised in the assessment, diagnosis and management of visual development and squints in children.
Paediatric nurse
A nurse specialised in dealing with children.
Paediatric Ophthalmologist
A surgeon specialised in treating eye problems in childhood.
Paediatrics
The branch of medicine concerned with children and their diseases.
Patching
Patching is a treatment for amblyopia (lazy eye). This treatment involves covering the good eye with a special sticky patch to make the brain use the lazy eye. This treatment is to make the vision better in the lazy eye and does not make a squint better. The other name used is occlusion treatment.
Pre-assessment
An appointment with the eye surgeon, orthoptist and nurse prior to an operation during which certain information is given and gained.
Prisms
Plastic lenses which can be fitted to a spectacle lense, on a temporary basis, to eliminate double vision.
Pupil
The black part in the centre of the eye. The pupil is a hole that the light passes through to reach the back of the eye. The pupil changes size to become smaller in bright light as the iris constricts and and larger in dim light as the iris relaxes.
Recovery area
This is the area (staffed by specialist recovery nurses) that patients are taken to immediately after their operation before being returned to the ward.
Refraction
Measuring whether glasses are needed or not. Usually performed by an optometrist or eye doctor.
Refractive error
The need for glasses i.e short sightedness or long-sightedness. This is what the optometrist measures when you go to the opticians and he puts lots of lenses in front of your eyes.
Retina
The layer at the back of the eye which receives the picture and converts it into an electrical signal to be sent to the brain. It is like a wallpaper on the inside of the eye.
Squint
Mis-alignment of the two eyes. Eyes may be turned in (convergent squint) or out (divergent squint). Less commonly the eyes may be mis-aligned vertically i.e one eye is higher than the other. Strabismus is another word for squint common in North America.
Strabismus
Another word for squint (commonly used in North America).
Suture
Another word for stitch. Most stitches used in squint surgery dissolve on their own.
Syndrome
A combination of symptoms and signs occurring together indicating a certain disease or disorder.
Visual acuity
A measure of how well the eyes see. In adults we measure this by asking the patient to read the letters on the eye chart. Normal vision is 6/6 in the UK (because the test chart is 6 metres away) and 20/20 in the USA (because the test distance is measured in feet....the chart is 20 feet away from the patient). In children who cannot read letters we measure visual acuity using pictures or other clever tests!