Full Version: Light in the darkness
If I lay comfortably in a dark room for long enough without actually being tired or sleepy, my eyes adjust and the purple clouds subside, and if it's dark enough I'll see only darkness. But if I then close my eyes gently, many times I'll see the inside of my eyelids, appearing illuminated in a yellowish light with a tinge of orange. And if I open my eyes again, it is gone replaced by the darkness. And so on, and so on. What is the source of this light which seems to reflect from my eyelids when I'm in a completely dark room?
1: Physiol Bohemoslov. 1989;38(4):289-309. Related Articles, Links
Purkynĕ's description of pressure phosphenes and modern neurophysiological studies on the generation of phosphenes by eyeball deformation.
Grüsser OJ, Grüsser-Cornehls U, Hagner M, Przybyszewski AW.
Department of Physiology, Freie Universität, Berlin, Germany.
(a) When a subject indents one of his eyeballs in total darkness, he immediately perceives light extending slowly across the whole visual field of the indented eye. The appearance and the time course of these pressure or deformation phosphenes are described. (
With simultaneous binocular indentation of the eyeballs a flickering patterned phosphene is observed. © A short history of the research on pressure phosphenes and its consequences for the theories of vision is presented. (d) Purkynĕ's observations of monocular deformation phosphenes are described. He repeatedly noted patterned light structures, which most observers only perceive with simultaneous binocular eyeball deformation. It is suggested that Purkynĕ's deviating observations were caused by amblyopia of one eye. (e) The neurophysiological basis of the monocular pressure phosphenes was investigated by means of microelectrode recordings from single optic tract fibers. The activity of single retinal ganglion cells (on-center, off-center neurons, latency class I [Y-neurons] or latency class II [X-neurons]), was recorded in anaesthetized cats. Eyeball deformation in total darkness led to an activation of the on-center ganglion cells, while the off-center ganglion cells were inhibited. The latency and strength of this activation or inhibition varied considerably between different neurons, but were fairly constant in the same neuron when the eyeball indentation was repeated after a pause of 1-3 min. The latency and strength of neuronal activation or inhibition seemed to be dependent mainly upon the neuron location relative to the point of eyeball indentation. Some on-center neurons also exhibited a short activation at "deformation off". (f) The antagonistic response type of on-center and off-center ganglion cells was also observed when the eyeball was deformed as a hydrostatic open system and the intraocular pressure was kept at 25 mm Hg basic pressure. (g) Dark adaptation up to 45 min affected the deformation responses of retinal neurons only to a small degree, if at all. This corresponds to the observation that deformation phosphenes in a human observer changed little during the course of dark adaptation. (h) We assume that the activation of on-center and inhibition of off-center ganglion cells by eyeball deformation are caused by retinal stretching, which also leads to horizontal cell stretch. Stretching the horizontal cell membrane probably generates an increase in membrane sodium conductivity and a depolarization of the membrane potential. This depolarization of the horizontal cell membrane potential is transmitted either directly or indirectly (via receptor synapses) from the horizontal to the bipolar cells.(ABSTRACT TRUNCATED AT 400 WORDS)
Publication Types:
Historical Article
Research Support, Non-U.S. Gov't
PMID: 2531426 [PubMed - indexed for MEDLINE]
Purkynĕ's description of pressure phosphenes and modern neurophysiological studies on the generation of phosphenes by eyeball deformation.
Grüsser OJ, Grüsser-Cornehls U, Hagner M, Przybyszewski AW.
Department of Physiology, Freie Universität, Berlin, Germany.
(a) When a subject indents one of his eyeballs in total darkness, he immediately perceives light extending slowly across the whole visual field of the indented eye. The appearance and the time course of these pressure or deformation phosphenes are described. (
With simultaneous binocular indentation of the eyeballs a flickering patterned phosphene is observed. © A short history of the research on pressure phosphenes and its consequences for the theories of vision is presented. (d) Purkynĕ's observations of monocular deformation phosphenes are described. He repeatedly noted patterned light structures, which most observers only perceive with simultaneous binocular eyeball deformation. It is suggested that Purkynĕ's deviating observations were caused by amblyopia of one eye. (e) The neurophysiological basis of the monocular pressure phosphenes was investigated by means of microelectrode recordings from single optic tract fibers. The activity of single retinal ganglion cells (on-center, off-center neurons, latency class I [Y-neurons] or latency class II [X-neurons]), was recorded in anaesthetized cats. Eyeball deformation in total darkness led to an activation of the on-center ganglion cells, while the off-center ganglion cells were inhibited. The latency and strength of this activation or inhibition varied considerably between different neurons, but were fairly constant in the same neuron when the eyeball indentation was repeated after a pause of 1-3 min. The latency and strength of neuronal activation or inhibition seemed to be dependent mainly upon the neuron location relative to the point of eyeball indentation. Some on-center neurons also exhibited a short activation at "deformation off". (f) The antagonistic response type of on-center and off-center ganglion cells was also observed when the eyeball was deformed as a hydrostatic open system and the intraocular pressure was kept at 25 mm Hg basic pressure. (g) Dark adaptation up to 45 min affected the deformation responses of retinal neurons only to a small degree, if at all. This corresponds to the observation that deformation phosphenes in a human observer changed little during the course of dark adaptation. (h) We assume that the activation of on-center and inhibition of off-center ganglion cells by eyeball deformation are caused by retinal stretching, which also leads to horizontal cell stretch. Stretching the horizontal cell membrane probably generates an increase in membrane sodium conductivity and a depolarization of the membrane potential. This depolarization of the horizontal cell membrane potential is transmitted either directly or indirectly (via receptor synapses) from the horizontal to the bipolar cells.(ABSTRACT TRUNCATED AT 400 WORDS)Publication Types:
Historical Article
Research Support, Non-U.S. Gov't
PMID: 2531426 [PubMed - indexed for MEDLINE]
Yes, I've heard of and seen pressure phosphemes. But this is not the same situation which is why I specified that I've gently closed my eyes. In fact it only happens when there isn't pressure on my eyes. Also, why do I see the features of the inside of my eyelid rather than the patterns of the receptor cells in my eyes.
I conjecture that your eyelids are causing pressure on your eyes, or you have a fluid buildup in your eyeballs, thus creating the type of stress for pressure phosphenes . When it comes to seeing the details of your inner eyelid, that is possible if the sun or a bright light is shining through the eye membrane.
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