The orthoptist takes a detailed visual history from Peter and considers the following potential diagnoses:
- Double vision (diplopia) can cause a person to see two images of the same object. There are two main types of diplopia – monocular or binocular. Binocular double vision affects both eyes. If either eye is covered, the double vision stops. Monocular double vision affects only one eye – if the other eye is covered, the double vision continues. It is quite rare. Stroke survivors who experience double vision may not always report it.
- Eye muscle imbalance problems can cause the eyes to be misaligned and prevent them from working well together as a pair (impaired binocular single vision). Muscle imbalance problems can cause the eye to be unnaturally deviated either horizontally or vertically. Changes in eye balance can occur as a result of changes in glasses prescription, tiredness or a deterioration in general health and can cause people to report blurred vision, double vision or eyestrain/headaches. Prolonged eye muscle imbalance problems can lead to a visible squint or defective 3D vision (stereoacuity).
- Defective eye movements can result in the eyes being poorly co-ordinated and can occur for a variety of reasons e.g. multiple sclerosis or stroke. Defective eye movements can have a detrimental effect upon every day activities such as reading or walking. This can result in difficulties with comfortable co-ordination of the eyes during close work activities or balance issues when mobilising. They are often difficult for people to describe and for clinicians to identify but if present, can be very debilitating.
- Lost or incorrect glasses can often give the impression that a patient has visual problems after stroke. It is important to know if the patient wears glasses (for distance or reading) and if their prescription is current. The correct spectacle prescription is a useful way of ruling out some other visual problems.
The orthoptist decides that Peter needs an assessment of his eye movement systems and reading.
Page last reviewed: 29 Jul 2021
