Afterimages: a lesser known aspect of CBS

Scot Muirden 

In the unusual world of CBS, there are all sorts of phantom visions that are encountered. Animals, buildings, figures and faces feature prominently in reading material but there are some lesser known aspects of CBS that people may not know of or have read about. One of these is the concept of afterimages. Everyone - at some point in their life - naturally experiences an afterimage. It can happen after looking at something very bright (like the sun) and then looking away. A replica of the vision usually lasts a matter of seconds; the afterimage quickly fades.

However, there are peculiar forms of afterimage which can be quite unsettling when experienced. Take for example Ivy who lives with macular degeneration. One Spring morning she is out in her garden admiring the recent blooms. A flower captures her attention: a white-petalled flower that bears a distinctive red dot at the innermost part of each petal. It resembles a kind of distorted Japanese flag. Later, Ivy comes back inside her home and is standing by her kitchen benchtop waiting for her kettle to boil. The bench top is white. As she takes in the whiteness, to her astonishment that white-petalled flower with inner red circles is now in perfect view. It’s as visible now as it was when she had earlier inspected it.

 

 (The flower previously seen in the garden is now presenting on the kitchen benchtop.) 

 

This condition is known by the medical name palinopsia. It is derived from the Greek ‘palin’ meaning again and ‘opsia’, seeing. So it literally means ‘seeing again’. And this occurs even though the original image perceived has now long gone from view. That original image either persists - or reappears - in a different visual setting. In some instances, the person does not see just one but a whole row of multiples of the exact same image: such as seeing a row of identical yellow toasters above the TV. In the instance below, the person with palinopsia has seen the distinctive mural design and this has been cleverly transplanted onto a passing woman's jeans.

 

(Image kindly supplied by Victoria Hamilton) 

 

Palinopsia is not restricted to just this form though. In another instance, a bird moving across the visual field is seen as a series of distinct, individual images like separate frames from a cartoon or slowed down movie reel. For others, discrete separate images are not seen but rather an object is perceived that leaves a visual trail as it moves. This is like a reverberating echo of the image as illustrated by the video below.

 

 (Video kindly supplied by Victoria Hamilton)

 

All these examples of palinopsia (afterimages) are recognised as a medical symptom of some form of distortion to normal visual processing. Palinopsia can occur from a wide range of medical conditions. These include: migraine, epilepsy (seizures), multiple sclerosis, brain injury (eg. stroke or tumour), high blood sugar (hyperglycemia), significant lack of sleep or a side effect of a prescribed medication.

Palinopsia can also be a component of Charles Bonnet syndrome although it may only comprise ~10% of all CBS experiences. With the more common form of CBS, the phantom images tend to bear no relationship to anything recently seen in everyday life. In fact, some even say that their phantom figure, object or pattern is unfamiliar to them. Yet with palinopsia, it is very familiar because the image was so recently seen.

Many CBS experiences of visual images have no real or clear relationship with the outside world. What makes palinopsia interesting is that these afterimages are drawn from recent, real life visual experiences. It’s just that they’re presenting out of place or warped in some fashion.

 

Summary

CBS is rich in its variety of visual experiences. Some only see a pattern or coloured blob in a small region of their visual field. Others are stunned by full panoramic views. In the mix too, are various forms of afterimages. If you (or a loved one) seem to be experiencing a form of palinopsia, be wary to automatically assume it is CBS. As palinopsia occurs for a wide number of medical conditions, it is advisable to consult a suitable medical practitioner to establish which may be relevant in your circumstance.