On Being Stoned
Charles T. Tart, Ph. D.
Chapter 6. Vision
MAN IS PRIMARILY a visual animal, both in terms of vision's being
his primary and generally most efficient way of perceiving his
environment, and in terms of visual styles' influencing his thinking,
imagining, and conceptualizing. Changes in visual experience while
intoxicated on marijuana are thus of particular interest. We shall
first consider phenomena related to visual perception of the external
world, then those related to visual imagery and hallucinations.
PERCEIVING THE EXTERNAL WORLD
Form and Organization
A very characteristic effect of marijuana intoxication is increased
perceptual organization ("meaningfulness"): "I
can see patterns, forms, figures, meaningful designs in visual
material that does not have any particular form when I'm straight,
that is just a meaningless series of shapes or lines when I 'm
straight" (6%, 6%, 29%, 37%, 19%).
The modal minimal level of intoxication for
this is Strongly (3%, 25%, 37%, 17%, 5%). The College-educated
experience this more frequently than the Professionals (p
|Figure 6-1. PERCEIVED FOCUS OF THE VISUAL FIELD
Note.In interpreting the "How Stoned" graphs, note
that the percentage of users plotted at each level is the percentage
indicating that level as their minimal level of intoxication for
experiencing that particular effect. Thus. a drop in the curve
with increasing minimal level of intoxication does not mean that
fewer users experience that effect at higher levels. but that
fewer give a higher level as their minimal level for experiencing
A common effect that also reflects this increased perceptual organization
of the visual field is "Things seen are seen more sharply
in that their edges, contours stand out more sharply against the
background" (13%, 13%, 31%, 30%, 11%). The contrary effect,
"My vision tends to be somewhat blurry; if I try to examine
something visually, I can't focus as sharply as when straight"
(32%, 29%, 25%, 9%, 3%) occurs much less frequently (p
<.001), as shown in Figure 6-1. Blurriness of vision is associated
with higher levels of intoxication (1%, 13%, 18%, 21%, 11%) than
sharpening (6%, 41%, 24%, 10%, 2%), as shown in the figure (p
Visual blurriness is reported somewhat more frequently by women
than by men (p <.05), and is reported as occurring
at lower minimal levels of intoxication by Occasional users in
comparison to Weekly or Daily users (p <.05, overall).
A fairly frequent effect that also illustrates reorganization
of the visual field is "The face of another person will
change even as I watch it, so he keeps changing from one different
person to another" (36%, 21%, 23%, 11%, 6%). This is
a high-level effect (2%, 3%, 11%, 19%, 17%), although many (47
percent) users did not rate level. Users of Psychedelics experience
it more frequently than Non-users (p <.01). Meditators
experience it more frequently than Ordinary Users (p <
.05), with neither group significantly differing from the Therapy
and Growth group.
|Figure 6-2. PERCEIVED COLORS WHEN STONED|
Like form, color is an important aspect of visual organization,
and perceptual changes here are common: "I see new colors
or more subtle shades of color than when I'm straight"
(10%, 18%, 30%, 19%, 21%). The contrary effect, "Colors
get duller, not as vivid," is rare (62%, 23%, 8%, 3%,
1%), as shown in Figure 6-2 (p <.001). Color perception
is enhanced at low levels of intoxication (17%, 31%, 27%, 7%,
4%). Most users (67 percent) could not rate the minimal level
for color dulling (6%, 13%, 6%, 5%, 3%), and this distribution
of levels does not differ significantly from that reported for
The Therapy and Growth group tends not to see new colors as frequently
as the Meditators and Ordinary Users (p <.05, overall). The
Professionals have to be more intoxicated than the College-educated
for colors to get duller (p <.05).
An important element of visual organization is the dimension of
perceived depth. Four items deal with changes in perceived
depth. We shall describe each separately before considering their
A common effect is "When I look at pictures they may acquire
an element of visual depth, a third-dimensional aspect that they
don't have when straight" (13%, 12%, 34%, 23%, 15%),
which begins in the low-middle range of intoxication (4%, 26%,
32%, 12%, 7%). One of my informants, known for his excellent phenomenological
description of marijuana intoxication (Anonymous, 1969), describes
how dramatic this can be: if, while intoxicated, you look at a
color photograph or picture postcard of a scene with natural depth
in it, and look with one eye through a pin-hole close enough to
the picture so that its borders cannot be seen, the two-dimensional
representation will suddenly turn into three dimensions, as if
you were looking at the actual scene.
A converse and rare depth effect is "The world looks flat:
it lacks the third dimension of depth" (55%, 27%, 9%,
5%, 1%). Most users (61 percent) did not rate the intoxication
level for this (4%, 8%, 15%, 7%, 5%).
A fairly frequent depth effect is "Visual depth perception
changes, so that near objects seem much nearer and far objects
seem much further away" (32%, 19%, 29%, 11%, 5%), what
might be called a magnification of visual depth. This is
reported as occurring in the higher intoxication levels (1%, 14%,
25%, 17%, 6%).
The visual depth magnification effect seems to be a long-term
effect, persisting steadily over time, compared to an infrequent
effect that might be termed a visual depth jiggle: "Objects
or people may seem to get visually nearer or further as I look
at them without their actually moving at all" (39%, 23%,
21%, 10%, 5%). Many users (46 percent) did not rate the intoxication
level for this (2%, 9%, 17%, 19%, 7%), although it is generally
perceived at higher levels. Experience with using marijuana modulates
this effect, whether factored in terms of total use or frequency
of use in the last six months. Both Moderate Total users and Weekly
users need to be more intoxicated for this experience than Light
or Heavy Total users in the one case (p <.05) or Occasional
or Daily users in the other case (p <.01).
|Figure 6-3. DEPTH PERCEPTION|
Note.For guide to interpreting the "How Stoned" graph,
see note on Figure 6-1.
All four of these intoxication effects on visual depth perception
are compared in Figure 6-3. The illusion of depth in flat pictures
and the general magnification of depth both occur more frequently
than the world's appearing flat or the depth's changing even as
the user looks (jiggling) (p < < <.001), and
the jiggling of perceived depth requires a higher intoxication
level (p <.02).
Two common phenomena represent an increased centrality of vision,
enhancement of the focused object at the expense of peripheral
objects: "Things outside the center of my visual field,
things in the periphery of my vision look different when I'm not
looking directly at them than when I look directly at them. E.g.,
I might see a door as open when I'm not looking directly at it,
but when I look directly at it, it is closed" (19%, 21%,
32%, 19%, 7%) and "My visual perception of the space around
me is changed, so that what I'm looking at is very real and clear,
but everything else I'm not focusing on visually seems further
away or otherwise less real or clear" (23%, 15%, 27%,
19%, 13%). Both have a modal level of intoxication of Strongly
(3%, 23%, 29%, 17%, 5% and 4%, 17%, 25%, 17%, 6%, respectively).
Neither the frequency of occurrence nor level of intoxication
distributions differ for these effects.
Several background factors affect whether things in the periphery
change. Younger users and Non-users of Psychedelics report this
phenomenon as occurring more frequently (p <.05, p
<.01, respectively) compared to Older users and Users of Psychedelics.
Further, Users of Psychedelics are more variable in their ratings
for this than Non-users (p <.05) and generally require
higher levels of intoxication.
With respect to increased centrality of vision, Daily and Weekly
users must be more intoxicated than Occasional users (p
Another common phenomenon is "There is a sensual quality
to vision, as if I were 'touching' the objects or people I am
looking at" (22%, 16%, 31%, 19%, 9%), which occurs at
higher levels of intoxication (5%, 14%, 23%, 25%, 5%). This is
reported more frequently among the College-educated than among
the Professionals (p <.05). This effect is also reported
most frequently among the Heavy Total users (modal frequency category
is Very Often/Usually), next most frequently by the Moderate Total
users, and least frequently by the Light Total users (p
<.01 for the Heavy-Moderate, p <.01 for the Heavy-Light
comparison, Moderate-Light not differing significantly). Further,
the Moderate and Light Total use groups report higher minimal
levels of intoxication for this than the Heavy group (p
The final infrequent effect on perceiving the external world is
"Everything I look at seems to vibrate or pulse, as if
it had a life of its own" (23%, 31%, 29%, 8%, 7%), which
occurs at the higher intoxication levels (1%, 5%, 15%, 23%, 19%).
Users of Psychedelics report a higher level of intoxication (mode
at Maximum) for this than Non-users (p <.05).
VISUAL IMAGERY AND HALLUCINATION
A very characteristic phenomenon is enhanced visual imagery: "If
I try to visualize something, form a visual image, I see it in
my mind's eye more intensely, more sharply than when straight"
(12%, 3%, 22%, 25%, 35%). This begins occurring in the low-middle
ranges of intoxication (13%, 33%, 24%, 11%, 3%).
A specific illustration of this is the common effect, "I
have more imagery than usual while reading; images of the scenes
I'm reading about just pop up vividly" (15%, 11%, 24%,
27%, 15%), which also occurs at the lower levels of intoxication
(13%, 33%, 22%, 4%, 2%). The Weekly users have to be somewhat
more intoxicated to experience this than the Occasional users
(p <.05), with a suggestion that the Daily users do
not have to be as intoxicated as the Weekly users (p <
.10). While the general enhancement of visual imagery occurs more
frequently than visual imagery accompanying reading (p
<.01), the distribution of levels of intoxication does not
A related phenomenon, described fully in Chapter 15, "When
thinking about things while stoned, there are visual images that
just automatically go along with thinking," a very common
effect, which occurs at Moderate levels of intoxication.
Two frequent phenomena stand midway between perceptual alteration
of real phenomena and hallucination: "I see fringes of
colored light around objects (not people), what people have called
the 'aura'" (46%, 21%, 20%, 8%, 1%), and "I see
fringes of colored light around people (not objects), what people
have called the 'aura"' (50%, 23%, 19%, 5%, 1%).
Many users (57 percent, 59 percent, respectively)
did not rate the level of intoxication for this, but for those
who did, it was generally rated in the highest ranges (1%, 4%,
15%, 10%, 13%, and 3%, 2%, 9%, 12%, 15%, respectively).
Seeing an aura around objects is somewhat more common in
the Younger group than in the Older group (p <.05);
more common in Heavy Total users of marijuana than in Moderate
(p <.05) and Light Total users (p <.05);
more common in Users of Psychedelics than in Non-users (p
<.05). Seeing auras around people is also more frequent
in Users than in Non-users of Psychedelics (p <.001).
Pure visual hallucination is an infrequent phenomenon: "With
my eyes open, I can see things that aren't there, i.e., for which
there is no real visual basis. E.g., if you look at stains on
a wall and see a design, that's an illusion; you are altering
something there. This question deals with seeing something when
there's nothing there, such as seeing a pattern or object
on a perfectly blank wall" (33%, 23%, 27%, 7%, 9%). Although
many (45 percent) users did not rate intoxication level, when
it does occur this is a high-level phenomenon (1%, 6%, 10%, 20%,
18%). It is reported more frequently in the Younger Group (p
<.01), and more frequently in the Heavy and Moderate Total
use groups compared to the Light Total use group (p <
A number of users wrote in additional visual effects in the final
part of the questionnaire.
Three users mentioned stroboscopic effects on vision: (1) "Old-time
movie effect, where people move in phases as in a movie running
too slow" (Sometimes, Strongly); (2) "I see in frames
like a movie, only slowed down" (Rarely, Strongly); and (3)
"Vision distorted as if seeing world with big strobe light
flickering overhead" (Sometimes, Maximum).
"I see movement in things that I focus on, a matchbook cover
with a geometrical design shifted like a light show movie; the
more stoned, the bigger they are of movement" (Sometimes,
"I find a continuum which starts with things' being two-dimensional
and progressing to deep three-dimensional. I find I can stop anywhere
on it" (Usually, Maximum).
"I can see the texture of the air in little swirling dots"
"Things inanimate, like a pile of clothes, seem to come to
life;" (Sometimes, Strongly).
"Much more fun to watch color TV or newscasts" (Sometimes,
"Am able to see mythical, angel-like creatures, which seem
to be personal spirits" (Rarely, Maximum).
"Figure-ground shifts become more frequent and easier to
control when stoned" (Sometimes, Strongly).
"I get more, and more pronounced, afterimages" (Rarely,
"Aesthetic perception augmented re Cezzane [sic]: see interview
with Allen Ginsberg, Paris Review #37" (no specification
of frequency or levels).
LEVELS OF INTOXICATION FOR VISUAL PHENOMENA
The grouping of visual phenomena by intoxication levels is presented
in Figure 6-4 and is highly significant (p <<<
.0005). At the lowest levels, vision may sharpen up, patterns
may appear, and colors may be affected. Further up, visual imagery
is enhanced, and vision may become more central with depth magnified.
Between Strongly and Very Strongly intoxicated, a sensual quality
is frequently added to vision, and the external visual world may
become unstable, with blurring and jiggling in depth. As one goes
higher, vision may pulse, faces may change, auras may appear around
objects, and at the highest level the maximal alteration of the
visual world may occur with hallucinations and auras around people.
FIGURE 6-4. INTOXICATION LEVELS, VISUAL PHENOMENA
|Just ||Fairly ||Strongly ||Very|
|Type size code:|
|AURAS AROUND PEOPLE|
|PULSING OF VISION|
|AURAS AROUND OBJECTS|
|JIGGLING OF DEPTH|
|SENSUAL QUALITY TO VISION|
|MORE CENTRALITY OF VISION|
|Flat quality to the world|
|PERIPHERAL VISION CHANGES|
|PATTERNS, MEANING IN AMBIGUOUS MATERIAL|
|THIRD DIMENSION ADDED TO PICTURES|
|VISUAL IMAGES AUTOMATICALLY ACCOMPANY THOUGHT|
|VISUAL IMAGERY MORE VIVID|
|NEW SHADES OF COLOR|
|VIVID IMAGERY WHILE READING|
|colors get duller|
|CONTOURS GET SHARPER|
|Just ||Fairly ||Strongly ||Very|
Table 6-1 summarizes the effects of background factors that have
relatively linear effects. Imagery automatically accompanying
reading and visual jiggle appear to have a curvilinear relationship
to drug experience, occurring more frequently and at lower levels
of intoxication with moderate experience than with little or much
In general, more drug experience goes with sensuality and unusual
visual experiences, and with more intoxication required for the
possibly undesirable effects of blurriness and pulsing of vision.
EFFECTS OF BACKGROUND FACTORS ON VISION
|More Drug Experience||More frequent:|
Sensuality of vision
More intoxicated for:
Pulsing of vision
Peripheral vision changes
More centrality of vision
Peripheral vision changes
Less intoxicated for:
Sensuality of vision
|Older|| ||Less frequent:|
Peripheral vision changes
|More educated|| |
More intoxicated for:
Patterns in ambiguity
Sensuality of vision
|Males|| ||Less frequent:|
|Therapy & Growth|| ||Less frequent:|
In general, the specific changes in visual perception brought
about by marijuana intoxication may be seen as particular manifestations
of a general change in what we might call the visual pattern-making
process. It is common to assume that we passively "see"
what is out there, that the qualities of the visual world are
inherent in the physical properties of objects and space. Modern
psychological investigations have made it clear that seeing is
a very active and complex process in which we construct
the visual world from the flux of visual sensations reaching us.
That is, patterns, forms, objects, recognizable people, etc. exist
in our minds as a construction from visual data. We are so used
to doing this automatically that it seems as if the visual world
were given. This active nature of visual perception is true of
all sensory modalities.
The patterns that are formed from visual data are organized into
a degree of complexity and familiarity that is optimal for surviving
in the world around us. Detecting a potential predator concealed
in some bushes has survival value; seeing a potential predator
in every ambiguous visual input is not conducive to survival of
the organism. Thus we may conceive of some optimal level (actually
a dynamic range) of
patternmaking activity, of organization of ambiguous (and not
so ambiguous) visual data into meaningful percepts. Raise this
level too high and we have illusion or hallucination. Lower this
level too much and we have stupidity.
Marijuana intoxication seems to raise the level a fair amount,
more so with increasing levels of intoxication. Thus patterns
form from ambiguous material, contours are sharpened, central
visual phenomena are enhanced at the expense of peripheral phenomena,
depth is magnified and more subtle shades of color are perceived.
With eyes closed, visual imagery is enhanced.
Such a raising of level of the patterning mechanism is a two-edged
sword. On the one hand, it may genuinely result in perceiving
useful patterns and meanings that would have been overlooked.
On the other hand, meaning may be falsely attributed to phenomena
that have no such meaning. Many users seem to be aware of this
combined advantage-disadvantage of marijuana intoxication and
to compensate for it by requiring more data than usual before
making a judgment or carrying out a consequent action. Others
naively accept everything seen while intoxicated as true. This
same dual aspect of raising the level of patternmaking activity
applies, of course, to all sense modalities and cognitive processes.
Whether the proportion of naiveté and sophistication is
any different from that of ordinary people in everyday life is
a moot question.
1. For all items, frequency of occurrence
data is always presented in the order Never, Rarely, Sometimes,
Very Often, Usually, and intoxication level data in the order
Just, Fairly, Strongly, Very Strongly, Maximum. These will not
always add up to 100 percent because of variable numbers of respondents'
skipping various questions and/or rounding errors. (back)
2. Readers interested in this rather exotic
effect may see Ellison (1962) and Kilner (1965). Most of the writing
on this subject is mystical, but the above references do attempt
some objective treatment of the phenomenon. (back)
3. In general, intoxication effects that are
two levels or more apart in this type Of graphical plot will be
different enough to reach statistical significance. (back)
4. The "optimal" level is quite
situation-specific; depth jiggle, for example, may be quite amusing
and enjoyable during a relaxed evening at home (safe conditions)
but might be a pronounced disadvantage while working at some crucial
task that required very accurate depth perception. (back)