• Accommodation - the focusing mechanism of the eye.
  • Accommodative esotropia - a convergent squint, the size of which is influenced by the focusing mechanism of the eye.
  • Adjustable suture - a form of stitch in an eye muscle that can be adjusted after the operation (with the patient awake), to improve the alignment of the eyes.
  • Amblyopia - is a decrease in a child’s vision that can happen even when there is no problem with the structure of the eye.
  • Anaesthetist or anesthesiologist (US) - a doctor who specialises in administering anaesthetics.
  • Analgesia - any type of medication which relieves pain without causing a loss of consciousness.
  • Anisometropia - unequal refractive error between the two eyes.
  • Astigmatism - a visual defect in which the unequal curvature of one or more refractive surfaces of the eye, usually the cornea, prevents light rays from focusing clearly at one point on the retina, resulting in blurred vision.
  • Atropine penalisation - paralysis of the focusing mechanism of the non-amblyopic eye with atropine eye drops, used to stimulate an improvement in the vision of the amblyopic eye.
  • Binocular vision - 3-dimensional vision.
  • Botulinum toxin (Botox) - a potent naturally occurring neurotoxin, which is widely used in many fields of medicine to produce a temporary paralysis of a muscle it is injected into.
  • Brown’s syndrome - a type of vertical squint characterised by difficulty moving the affected eye up and inwards.
  • Cataract - a cloudy lens.
  • Conjunctiva - the transparent membrane covering the sclera.
  • Cornea - the clear window at the front of the eye.
  • Cover test - part of an orthoptic examination used to assess a squint.
  • Cycloplegia - temporary paralysis of the focusing muscles of the eye caused by administering cyclopentolate or atropine drops.
  • Dissociated vertical deviation (DVD) - a form of intermittent vertical squint that is often seen in patients who have an infantile esotropia.
  • Duane's syndrome - a type of squint, which is present from birth, that is usually characterised by an inability to move one or both eyes outwards.
  • Esotropia - a convergent (inward turning) squint.
  • Exotropia - a divergent (outward turning) squint.