sacco-, sacc-, sacci- +

(Greek > Latin: bag, pouch)

Inflammation of the mucous membrane of the air sacs of birds.
1. Minute to-and-fro movements of the eyes.
2. The largest of the fixational eye movements, carrying an image across dozens to several hundred of the eye's photoreceptor (light-detecting) cells, including cones for detail and color vision and rods for low-light and peripheral vision.

People naturally hold microsaccades at bay momentarily when they perform precision tasks; such as, when shooting a rifle or when threading a needle.

The largest voluntary eye movements

When the eyes focus on something, they still jump imperceptibly in ways which turn out to be essential for seeing.

For decades, scientists have debated the purpose, if any, of these so-called fixational eye movements, the largest of which are called microsaccades. It has been demonstrated that microsaccades engender visibility when a person's gaze is fixed and that bigger and faster microsaccades work best.

Microsaccades may also shed light on subliminal thoughts. Recent research suggests that the direction of microsaccades, is aimed toward objects to which people are unconsciously attracted, no matter where they are actually looking.

Microsaccades alter the responses of other cells in the visual system. Without these movements, visual neurons would adapt to the unchanging stimulus by decreasing their activity resulting in fading vision.

—Excerpts from "Windows on the Mind"
by Susana Martinez-Conde and Stephen L. Macknik,
Scientific American, August, 2007; pages 40-47.
pseudosaccus (s), pseudosacci (pl)
An extensive, saccus-like (sac-like) separation in the wall of a spore resembling a saccus, but lacking the characteristic alveolate infrastructure.
saccade, rapid eye movement, saccaduc eye movement; saccadic movement
1. The act of controlling a horse quickly with a single strong pull of the reins.
2. The rapid involuntary movement of the eyes that occurs when an image of interest falls on the retina at a distance from the fovea (small depression), as normally occurs when reading the printed page.
3. The series of small, jerky movements of the eyes when changing focus from one point to another.
4. The abrupt rapid small movements of both eyes; such as, when the eyes scan a line of print.

The saccades can be divided into two distinct groups: the major saccades which are easily observed with the naked eye and the minor saccades that are virtually unobservable without special instrumentation.

The word saccade is borrowed from French. It is derived from Old French sachier, "to shake". In horse riding, a saccade is the brusque shaking given to the reins of a horse which is used as a signal to the horse by the rider.

Characterized by a series of quick, involuntary movements of the eyes when adjusting one's gaze while fixating on objects in sequence, as when reading printed materials.
Appearing like a sac, bag, or pouch.
sacciform, saccular
In the shape of a pouch or sac.
1. A small pouch; for example, the alveolar saccules (little air pouches) within the lungs.
2. Resembling a sac or saccule.
saccular aneurysm
A saclike bulging on one side of an artery.
sacculate, sacculated
1. Formed into or having a saccule, sac, or saclike dilation.
2. Having saccules.
sacculated stomach
A chambered stomach which helps to break down plant material; observed among arboreal old world monkeys.
1. A small bag; especially, for money.
2. The process of forming a sac or saccule.
3. A saccule or a group of saccules.
sacculation of the colon, haustra of the colon
The sacculations of the colon, caused by the teniae, or longitudinal bands, which are slightly shorter than the gut so that the latter is thrown into tucks or pouches.
A small sac.
sacculi alveolares
Saclike spaces budding outward from the terminal ends of the alveolar ducts of the lung and comprising two or more alveoli (tiny air sacs within the lungs where the exchange of oxygen and carbon dioxide takes place).