Peter Heath

the occipital lobe

The processing of visual information by the occipital lobe may be influenced by some forms of dementia, resulting in impaired cognitions. Faces may be seen in the shadows and in patterned wallpaper, and hallucinations may result. However, it's also possible for dementia sufferers to experience hallucinations with completely healthy eyes.

A few years ago, whilst sailing in the Caribbean Sea I was knocked unconscious by a blow to the head. The large metal boom made contact with my head precisely in the centre of the occipital lobe, and I regained consciousness with crystal clear diplopia. This condition persevered for a few years. Eventually my brain became accustomed to the separated images, and after a few more years, and with the aid of optical prisms in my eyeglasses, my brain gradually pulled those separated images together.

Agnes Houston, talking at a seminar on dementia and sight loss: "When I got a dementia diagnosis people knew I was having problems, so were quite understanding and looked at how they could help. Not so with this sight problem. Other people can't see anything wrong... [RNIB]* offered suggestions and little ways of stopping falling. I started to cry, just with relief that I'd got help for the first time."

(see Dementia and Sight Loss Interest Group, 2009)

* Royal National Institute of Blind People

See: Social Care Institute for Excellence - Dementia and sensory loss: Sight loss