Visual suppressions can be defined as any effect which worsens one's ability to percieve the external environment through their sense of sight.
This page lists and describes the various visual suppressions which can occur under the influence of certain psychoactive compounds.
Double vision can be the described as the experience of doubled vision identical to that which occurs when one crosses their eyes. Depending on the intensity, this can often result in a reduced ability to function and perform basic tasks which necessitate the use of sight.
However, this effect can easily be suppressed by simply closing one eye. This suggests that the effect may be occurring because the brain is simply overlaying the data received from both eyes on top of each other without rendering the information into a singular 3-dimensional image as it normally would in day to day life.
Pattern recognition suppression
Pattern recognition suppression can be defined as the experience of a partial to complete inability to mentally process perceivable visual information regardless of its clarity, detail and clearness. For example, although one may be able to see what is in front of them with perfect detail, they will have a reduced ability to register, label or understand what they are looking at. This can render even the most common of everyday objects as unrecognisable.
Pattern recognition suppression is most commonly directly induced by heavy dosages of antipsychotics and dissociatives. However, it can also be an indirect result of the long term memory suppression that often occurs during heavy dosages of psychedelics.
Vibrating vision (also known as nystagmus) can be defined as rapid and constant involuntary eye movements in which the eyes shift from left to right in such quick succession that one's vision begins to vibrate and blur. This can severely impair vision and result in a reduced ability to function and perform basic tasks which necessitate the use of sight.
Acuity suppression can be described as the experience of one's sense of vision becoming partially to completely blurred and indistinct. This effect may affect the entirety of one's vision or specific sections of it. Depending on its intensity, this can often result in a reduced ability to function and perform basic tasks which necessitate the use of sight.
Frame rate suppression
Frame rate suppression is a visual suppression where one's FPS (frames per second) are significantly reduced or slowed down. While under the influence of this effect, one might feel like their vision is lagging and frame-like (similar to a strobe light). This effect is generally reported with hallucinogens, particularly dissociatives.