Talk:Entoptic phenomenon

Comments

The correct rendering should be "endoptic" or "endo-optic", endo(=in, inside), and not ento-,which is misleading

• Nevertheless, "entoptic" is the standard term used in everything I've ever read about the subject. If you are aware of a journal style guide or medical dictionary or anything like that which recommends the use of "endoptic," please cite it. Dpbsmith (talk) 13:29, 22 August 2005 (UTC)

• The "ent-" prefix means "within". [1] AED 04:56, 23 August 2005 (UTC)

         (I assume "entoptic" wishes to signify "inside the optic") 

Endo-optic as in endoscopy, endogenous, etc;and not as in entropy or entomologist, where the prefix is "en", and not "entos"\"endo-".In Greek, the "t" of the word "entos" changes into delta when in a compound word.The 4th letter of the Greek alphabet-delta- being traditionally rendered with a "d", as in endogamy.Using the en of entropy, would give you "enoptic", and not entoptic (furthermore, "en" is not always used to denote "inside" , whereas "endo-" always is).

• Take it up with the lexicographers. "Entoptic" is the standard term. It's not Wikipedia's job to reform the language.

Main Entry: ent·op·tic

Pronunciation: ()ent-äp-tik

Function: adjective

lying or originating within the eyeball -- used especially of visual sensations due to the shadows of retinal blood vessels or of opaque particles in the vitreous body falling upon the retina

—Merriam-Webster, [2]

Dpbsmith (talk) 12:05, 24 August 2005 (UTC)

• Indeed. Wiki simply reflects the standard usage of a term and it's not our job to change it. I am not a linguist, however, I think it's safe to assume that languages borrow items from other languages quite often without strict adherence to whatever rules may have initially applied. This is particularly true of medical terminology. AED 17:27, 24 August 2005 (UTC)

Calling them "subjective" is not POV

They cannot be directly shown to others, hence they are subjective. Dpbsmith (talk) 01:03, 26 September 2005 (UTC)

E.g. "Do we ever see light": "We sometimes see entoptic phenomena or "spots before our eyes." All these are subjective sensations..."

The full comment was this: "This gives them a certain subjective and mysterious quality." "Mysterious" is certainly POV. All perception is subjective, but what is "a subjective quality"? Sure, you can't directly experience my entoptic phenomenon, but I can take you into the lab and show you all the entoptic phenomenon listed so that you can see them for yourself. It's an unnecessary comment in the article. AED 01:14, 26 September 2005 (UTC)

Purkinje figures?

I don't think these can be called "entopic phenomenon" since, as far as I know, one cannot see the Purkinje images in one's own eye. They are not seen by the person in whose eyes they appear, but by a second observer. Dpbsmith (talk) 01:48, 8 May 2006 (UTC)

I think Purkinje images gives a reasonable explanation of why they are entoptic phenomena. -AED 22:55, 16 June 2006 (UTC)

Whoops, got sidetracked for about six months. On reading Purkinje images, I agree that if that article is correct, then Purkinje images can be entoptic phenomena. The problem is I'm skeptical about the statement in that article that says

The third and fourth Purkinje images can be visible from within the eye itself. Light reflected away from the surfaces of the lens can in turn reflect back into the eye from the rear surface of the cornea.

It doesn't have a reference. The third and fourth Purkinje images are very dim to begin with, and an additional partial reflection from the cornea would make them dimmer still. And it doesn't explain how these reflections could possibly be close enough to being in focus on the retina to be visible.

Now, quite possibly I'm simply revealing my ignorance, but I'd certainly like to see a reference to the conditions under which the third and fourth Purkinje images in one's own eye can be visible to one's self. If true, I agree that this would certainly qualify as an entoptic phenomena. Dpbsmith (talk) 16:39, 26 December 2006 (UTC)

P. S. To confuse things further, it appears, at least from this reference[3], that "Purkinje's figures" or "Purkinje's images" can also refer to the vascular figure. Dpbsmith (talk) 16:40, 26 December 2006 (UTC)

I think the blood vessel shadows are called the Purkinje Tree, not the Purkinje images. You can't see the images, but you can see the tree in a simple classroom demonstration with a flashlight. Wandell 03:49, 11 November 2007 (UTC)

I think you're right. Certainly the Purkinje Tree is an entoptic phenomenon, and a dramatic one. Using a penlight to create a bright spot of light on the sclera is one good way to view it. Another way is to create a small pinhole e.g. in a black card or piece of aluminum foil, hold it in front of one's pupil, gaze at a uniformly lit surface (a blank wall or sheet of paper), and move the pinhole in small circles. The image is initially harder to see but "develops" over a few seconds and is much sharper and detailed than with the flashlight method. Dpbsmith (talk) 22:04, 11 November 2007 (UTC)

I added back a revised version of the Purkinje images relative to entopic images. The Wiki article on Purkinje images only covers I through IV, although Tscherning names and discusses V and VI, this last being an entoptic image. Tscherning also gives instructions on seeing it. I did this edit with mixed feelings, the image is very faint (Tscherning wrote: "we must pause to wonder at the enormous sensitiveness of the retina, for the brightness of the sixth image is really only 1/40,000 of that of the useful image") and the article doesn't mention much more visible phenomena such as Purkinje's blue arcs, Maxwell's spot, and other shadow images besides the blood vessels such as cornea wrinkles and the lens suture patterns. Please excuse and advise me of any mistakes I made with the edit (it was my first time). I shall try to add more later to this section and would appreciate help. Mwmauser (talk) 22:25, 22 November 2009 (UTC)

Entoptic vs endoptic vs entopic

éndon and entós both mean "within" and were used as locative prepositions (as well as en). Thus entoptic seems to be a valid blend (cf. entoderm, Entamoeba, etc.) although admittedly I don't find any natural Ancient Greek terms that used "endo-" or "ento-" as a prefix (all used "en-" as a locative as well as a lative prefix). (Don't confuse "éndon" with "endo-", the Old Latin prefix.) ṓps means "eye", ōpós being the genitive and ōp- the word stem, rendering -opic a valid alternative (cf. Cyclop, myopic etc.), albeit a rarer one. — Preceding unsigned comment added by 85.127.158.126 (talk) 18:03, 8 May 2012 (UTC)