What is eye accommodation, how it affects vision and behaviour, how to support students with accommodation dysfunction.
Accommodation is the adjustment of the optics of the eye to keep an object in focus on the retina as its distance from the eye varies.
There are generally three types of accommodative dysfunctions:
- accommodative insufficiency: difficulty efficiently sustaining focus at near. This is the most common type of accommodative dysfunction. The increased effort required to maintain clear vision at near can decrease performance on near tasks.
- accommodative infacility: difficulty to efficiently switch focus between near and far and back.
- accommodative spasm: a spasm of the focusing muscle which prevents the focusing muscles from fully relaxing. This generally causes blurry vision both near and far.
How eye accommodation affects vision
Eye accommodation can cause:
- blurred vision at near
- intermittent blurred vision at distance after reading
- difficulty switching between near and far
- eye strain
- headache, especially over the brow or temples
- eye fatigue
- general fatigue, especially later in the day
Symptoms are often worse:
- when tired
- later in the day
- during tasks
Behavioural symptoms of accommodative dysfunctions
Students with accommodative functions might:
- avoid detailed near work, for example reading, writing, or math
- find it difficult to sustain attention, especially on near work
- find it difficult to copy from the board
- hold material too close
- need frequent breaks to complete work
- make frequent mistakes, or have poor attention to detail
- have poor reading fluency or comprehension
What can be done to help children with eye accommodation
Treatment may include prescribing special lenses to help reduce eye strain.
In children, this may require two pairs of glasses, one for close-up and one for distance. Alternatively, bi-focals may be prescribed.
Recommendations for students with eye accommodation
Students may need:
- clearly presented worksheets and reading materials with a good contrast between text image and background, possibly enlarged or modified
- work to be presented on A4 rather than enlarge to A3
- their own copies of textbooks
- a reading slope
- extra time to study objects, demonstrations and visual displays closely
- modified programmes for PE and Games, as fast moving team games may be difficult
- to sit near the front of the classroom or to one side, depending upon the preferred angle of vision
- good levels of lighting, neither bright sunlight nor semi-darkness: the light source should come from behind the pupil and onto the object being viewed
- verbal descriptions of objects and displays which are outside the range of vision
- encouragement to use glasses, contact lenses and low vision aids
Find more information about eye accommodation on the BBC website.