Accommodative insufficiency (AI) is a condition in which people find it difficult to focus on near objects, to an extent which is unusually poor for their age group. The condition can occur in young people and children, and it is not caused by a problem with the lens of the eye. This means that accommodative insufficiency is different from the disorder known as presbyopia, commonly seen in people over the age of 40. In presbyopia, the lens loses its elasticity and its ability to adapt for near focusing. People with accommodative insufficiency typically experience eye fatigue when carrying out close work for a sustained period.
In adults, accommodative insufficiency is more common in women than men. Diagnosing the disorder includes ruling out other similar conditions such as farsightedness, where light focuses at a point behind the retina. Often the cause is unknown, but known accommodative insufficiency causes include certain drugs such as antidepressants, systemic diseases such as diabetes and sometimes eye disease.
The condition is sometimes associated with another disorder known as convergence insufficiency (CI). In convergence insufficiency, the eyes do not move inward effectively to allow accurate focusing on something near. This causes what is known as asthenopia, a situation in which people experience discomfort and difficulties performing the kinds of tasks where close focusing is necessary.
Common accommodative insufficiency symptoms include general tiredness when reading, headaches, blurred vision and eye strain. Loss of concentration and even motion sickness may occur. Individuals who spend a lot of time using computers, reading or carrying out detailed, close work are more prone to developing the symptoms associated with AI. Children with accommodative insufficiency may struggle with school work and may try to avoid reading whenever possible due to the discomfort they experience. Sometimes, children will assume that their experience is normal, with the result that their symptoms do not come to light until they reach adulthood.
Accommodative insufficiency treatment may involve managing an underlying condition, which could then lead to the problem resolving. A treatment known as vision therapy may benefit some patients. Vision therapy is suitable for both adults and children. The therapy involves an individually tailored program in which an optometrist uses eye exercises, lenses, eye patches and other equipment, working with the patient over a number of months. Spectacles or contact lenses may also be required, and these may be used without vision therapy for patients who are unable to commit to a program.