Balance (ability) in the context of "Eye irritation"

Gymnastics is a group of sport that includes physical exercises requiring balance, strength, flexibility, agility, coordination, artistry and endurance. The movements involved in gymnastics contribute to the development of the arms, legs, shoulders, back, chest, and abdominal muscle groups. Gymnastics evolved from exercises used by the ancient Greeks that included skills for mounting and dismounting a horse.

The most common form of competitive gymnastics is artistic gymnastics (AG); for women, the events include floor, vault, uneven bars, and balance beam; for men, besides floor and vault, it includes rings, pommel horse, parallel bars, and horizontal bar.

The human eye is a sensory organ in the visual system that reacts to visible light allowing eyesight. Other functions include maintaining the circadian rhythm, and keeping balance.

The eye can be considered as a living optical device. It is approximately spherical in shape, with its outer layers, such as the outermost, white part of the eye (the sclera) and one of its inner layers (the pigmented choroid) keeping the eye essentially light tight except on the eye's optic axis. In order, along the optic axis, the optical components consist of a first lens (the cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the focusing of light from the outside world; then an aperture (the pupil) in a diaphragm (the iris—the coloured part of the eye), which controls the amount of light entering the interior of the eye; then another lens (the crystalline lens) that accomplishes the remaining focusing of light into images; and finally a light-sensitive part of the eye (the retina), where the images fall and are processed. The retina makes a connection to the brain via the optic nerve. The remaining components of the eye keep it in its required shape, nourish and maintain it, and protect it.

Agility or nimbleness is an ability to change the body's position quickly and requires the integration of isolated movement skills using a combination of balance, coordination, speed, reflexes, strength, and endurance. More specifically, it is dependent on these six skills:

• Balance – The ability to maintain equilibrium when stationary or moving (i.e., not to fall over) through the coordinated actions of our sensory functions (eyes, ears and the proprioceptive organs in our joints);
• Static balance – The ability to retain the center of mass above the base of support in a stationary position;
• Dynamic balance – The ability to maintain balance with body movement; an equal distribution of weight;
• Speed – The ability to move all or part of the body quickly;
• Strength – The ability of a muscle or muscle group to overcome a resistance; and lastly,
• Coordination – The ability to control the movement of the body in co-operation with the body's sensory functions (e.g., in catching a ball [ball, hand, and eye coordination]).

In sports, agility is often defined in terms of an individual sport, due to it being an integration of many components each used differently (specific to all sorts of different sports). Sheppard and Young (2006) defined agility as a "rapid whole body movement with change of direction or velocity in response to a stimulus".

The sense of balance or equilibrioception is the perception of balance and spatial orientation. It helps prevent humans and nonhuman animals from falling over when standing or moving. Equilibrioception is the result of a number of sensory systems working together; the eyes (visual system), the inner ears (vestibular system), and the body's sense of where it is in space (proprioception) ideally need to be intact.

The vestibular system, the region of the inner ear where three semicircular canals converge, works with the visual system to keep objects in focus when the head is moving. This is called the vestibulo-ocular reflex (VOR). The balance system works with the visual and skeletal systems (the muscles and joints and their sensors) to maintain orientation or balance. Visual signals sent to the brain about the body's position in relation to its surroundings are processed by the brain and compared to information from the vestibular and skeletal systems.

Acrobatics (from Ancient Greek ἀκροβατέω (akrobatéō) 'walk on tiptoe, strut') is the performance of human feats of balance, agility, and motor coordination. Acrobatic skills are used in performing arts, sporting events, and martial arts. Extensive use of acrobatic skills are most often performed in acro dance, circus, gymnastics, and freerunning and to a lesser extent in other athletic activities including ballet, slacklining and diving. Although acrobatics is most commonly associated with human body performance, the term is used to describe other types of performance, such as aerobatics.

The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts:

• The cochlea, dedicated to hearing; converting sound pressure patterns from the outer ear into electrochemical impulses which are passed on to the brain via the auditory nerve.
• The vestibular system, dedicated to balance.

The inner ear is found in all vertebrates, with substantial variations in form and function. The inner ear is innervated by the eighth cranial nerve in all vertebrates.