Acquired cognitive impairment is a term used to describe a wide variety of conditions that impair brain function and memory. The most common condition is dementia, but others include stroke, brain injuries and psychiatric disorders.

Patients with cognitive impairment can have difficulty in remembering details of eye examinations or whether they have had one. The impairment can also affect their personality. If possible, you should, therefore, have a relative or carer present during the examination.

Patients with cognitive impairment can have the same range of visual problems as the general population but are also susceptible to specific ocular conditions, including colour vision changes and reductions in contrast sensitivity which may influence your decision whether to provide a tint.

Cognitive impairment may also cause cortical visual loss.