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accommodation - the ability of the eye to change the focus of the eye from distant to near objects. This process is achieved by changing the curvature of the lens. At rest the lens is focused for distant objects, and is able to focus on near objects by becoming more convex by the contraction of the ciliary muscles.
achromatopsia - the inability to see any colour. It is an extremely rare and serious form of colourblindness. Statistics report that this condition affects only one person in about 33,000.
acuity - the visual ability to resolve fine detail
adaptation - a change in an organism, resulting from exposure to certain environmental conditions, allowing it to respond more effectively to them.
Albers - was an important teacher of material and design at the Bauhaus school. Interactions of Color, the definitive work on color theory was written by Albers in America after fleeing Germany during World War 2.
albinism - failure to develop pigment particularly melanin in skin, hair and iris. Resulting in light-skinned with white hair and 'pink' eyes due to reflection of the choroid capillaries behind the retina. It is a genetic condition.
amblyopia - also termed 'lazy eye'. It is a
visual defect that affects approximately 2 or 3 out of every 100 children in
the United States.
Amblyopia involves lowered visual acuity (clarity) and/or poor muscle control
in one eye.
analogous colours are harmonious colours which sit side by side on the colour wheel, related colours such as yellow, yellow orange, orange, orange red, red.
aqueous humour - is the clear watery fluid that occupies the front chamber of the eye and nourishes the lens and the cornea. It also helps to give the eye shape, and protection. The aqueous humour is secreted by the ciliary body.
astigmatism - a condition in which the surface of the cornea is not spherical; causes a blurred image to be received at the retina. Condition can be corrected with glasses.
assymetry - lack of balance or symmetry.
Bauhaus - avantegarde Art and Design School based in Germany during the 1930's whose influence affected design internationally in architecture, industrial design and painting. The Bauhaus, a design workshop formed by architect Walter Gropius, was "dedicated to merging the traditionally separate disciplines of the fine and applied arts in an effort to improve the quality of modern life in all its aspects and, ideally, at every social level..."
binocular vision - the blending of the separate images seen by each eye into a single image, allows images to be seen with depth.
bioluminescence - the emission of visible light made by living organisms such as the firefly and various fish, fungi, and bacteria.
blindspot - A small area of the retina where the optic nerve enters the eye; occurs normally in all eyes. It results in a gap in the visual field which corresponds to an area of the retina where no visual cells are present.
cataract (of the eye) - a condition in which the eye lens loses its clearness. A gray-white film can be seen in the lens, behind the pupil. Cataracts are caused by a loss of function in the lens tissue, most often after 50 years of age.
central nervous system - the portion of the human nervous system consisting of the brain and spinal cord.
Chevreul - A physicist who published a theory of colour contrasts which influenced many art movements including the Impressionists, Post impressionists and Orphic cubism.
choroid - the layer filled with blood vessels that nourishes the retina.
chromosome - a threadlike linear strand of DNA and associated proteins in the nucleus of animal and plant cells that carries the genes and functions in the transmission of hereditary information.
ciliary -
muscles: the muscles that enable the lens to change shape for focusing
processes: the extensions of the ciliary body that secrete aqueous
humour.
colourblindness - a genetic condition
which results in an inability to distinguish certain colours and shades normally.
It does not mean that one sees everything in black, white, and gray. It is only
in extremely rare cases that no colors can be discriminated (known as achromatopsia).
It affects one in 12 men, and is rare in females because of the way it is passed
down through our genes. It occurs because of errors in the coding instructions
for the eyes visual pigment and as a result the eye will be sensitive to different
wavelengths of light (resulting in a color deficiency).
complementary colours are colours which are directly opposite on the colour wheel causing the highest of contrast for e.g.. red and green, blue and orange and purple and yellow.
cone - one type of specialized light-sensitive cells (photoreceptors) in the retina that provide sharp central vision and color vision. Found to be highly concentrated in fovea. (See also rod).
congenital - a condition present at birth. Often said to be an inherited characteristic or condition passed on from the parents or condition.
conjunctiva - The thin, moist tissue (membrane) that lines the inner surfaces of the eyelids and the outer surface of the sclera.
connective tissue - tissue that includes elastic, and reticular fibers, adipose tissue, cartilage, and bone. It forms the supporting and connecting structures of the body.
contract - draw inwards or together, make smaller, to shrink.
convergence - the coming together of lines (for e.g.) so as to meet in a point.
cornea - is part of eye's focusing system. It is the outer, transparent, dome-like structure that covers the iris, pupil, and anterior chamber.
demersal - organisms dwelling at or near the bottom of the sea or other body of water.
dilate - make or become wider or larger, to expand.
discordant colours - colour which clash and used for artistic effects to create impact for e.g. acrid green with flush pink.
diurnal - means to be active during the daytime rather than at night: diurnal animals. Animals that are mainly active at night are termed - nocturnal.
DNA - stands for deoxyribonucleic acid. This nucleic acid formation is the building blocks which form the genetic material of all cells, some organelles, and many viruses.
ecology - the branch of biology concerned with the relations between organisms and their environment.
elements of design - the basic components which make up any visual image. These are line, shape, colour, texture, tone, form.
emmetropia - another term for what is perfect vision, whereby the eye focusses the image onto the retina, rather than in front of behind it (as opposed to hyperopia and myopia).
endrogenous - originating or produced within an organism, a tissue, or a cell: endogenous secretions.
epithelium - tissue forming outer cellular layer of body surface or the lining of a body cavity. Epithelial cells are frequently secretors.
evolution - the theory that groups of organisms change with the passage of time, mainly as a result of natural selection, so that descendants differ morphologically and physiologically from their ancestors.
fovea - the central part of the macula
and provides the sharpest vision. This area of the retina is associated with
the highest concentration of cones and therefore the highest acuity. Humans
move their eyes so that images of interest are projected onto their foveas.
gene - a hereditary unit that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes exist in a number of different forms and can undergo mutation.
genetic code - the sequence of nucleotides (building blocks) in the DNA molecule of a chromosome that specifies the amino acid sequence in the synthesis of proteins. It is the basis of heredity.
genetic engineering - scientific alteration and manipulation of the structure of genetic material (DNA) in a living organism. Involves a series of procedures which uses and selected pieces (genes) of organisms.
genetics - is the field of biology devoted to understanding how characteristics are transmitted from parent to offspring. Genetics was founded with the work of Gregor Mendel, an Austrian monk who experimented with garden peas.
genus - a class of objects (organisms) divided into sub-species according to certain common attributes.
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hard edge - Hard Edge artists were concerned with the use of optics using geometric forms and hard edges to explore the action of colours in combination. Artists who utilised this style at some stage include Vasarelly, Bridget Riley and in Australian artists such as Lesley Dumbrell and Dale Hickey.
harmonious colours are colours which side by side on the colour wheel which means they are relative or analogous. For example - yellow, yellow/orange,orange, orange red, red.
hereditary - Information or traits passed on from individuals of one generation to their offspring and future generations.
hyperopia - also termed farsightedness. It is the ability to see distant objects more clearly than close objects, may be corrected with glasses or contact lenses (also see myopia).
ideogram - a symbol or picture representing an idea or concept rather than a word.
intraocular - situated or occurring within the eyeball.
iridescence - to produce a display of rainbowlike colors
iris - The colored ring of tissue suspended behind the cornea and immediately in front of the lens regulates the amount of light entering the eye by adjusting the size of the pupil. There are many variations on eye colour, for example many animals show iris colouration that allows them to blend into environment.
Itten - an art teacher at the famous Bauhaus who recognized the basic laws of colour and form, proportions, texture and rhythm as the foundation to any artwork. He wrote books on the seven colour contrasts influenced by Chevreul's colour theories.
lateral - is relating to the sides of an organism of structures
lens - the transparent, double convex (outward curve
on both sides), structure which serves to focus light onto back of eye (retina).
Normally enclosed within connective tissue eye capsule and held in position
by suspensory ligaments. By altering its shape
the lens can focus near and far objects.
macula - the small, sensitive area of the central retina which provides vision for fine work and reading. The macula consists of cones which lie roughly in the center of the retina.
macular degeneration - in people over sixty it is the most common cause of blindness, in which the macula becomes covered with scar tissue.
Magic Eye - computer-generated images/illustrations that when viewed normally, appear as simply a repeating pattern. However when viewed using a technique known as parallel vision ( i.e. focusing at a point well behind and beyond the image) a hidden image 'magically' presents itself to the viewer. Viewing Magic Eye images takes time to practice and build up the eye muscles and technique. For this reason Magic Eye images can actually be used incorporated into vision therapy.
Masaccio - 1401-1428. Italian painter of the Florentine school whose revolutionary use of linear perspective and mastery of light and shade profoundly influenced Renaissance painting.
melanin - dark brown pigment of many animals, giving colouration to skin hair, eyes etc.
metabolic processes - sequence of reactions each brought about by a different enzyme, leading to the formation of one or more functional products. Usually associated with digestion and energy distribution.
migratory - movement that is regularly or occasionally occurring from one region to another, e.g.: migratory birds, migratory pigment etc.
mutation - a sudden structural change within a gene or chromosome of an organism resulting in the creation of a new character or trait not found in the parental type.
myopia - also termed near sightedness It is the ability to see close objects more clearly than distant objects, may be corrected with glasses or contact lenses (also see hyperopia)
natural selection - the process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characters in increasing numbers to succeeding generations while those less adapted tend to be eliminated (also see evolution)
nocturnal - means to be mainly active at night.
Some animals need to have specific adaptations in order
to survive at night time (such as - special eyes to see in darkness, also see
rods). Animals that are mainly active in the daytime are
termed diurnal
op art - an art movement of the 1950 whose main concerns were hard-edge painting using colour and optics as its main theme
optical distortions - the use of colour combinations and shapes which trick the eye and brain
optical illusions -the use of shapes, colour, and line distortions which trick the eye and brain. When viewing confusing images, our brain can sometimes interpret visual information and cues incorrectly,or at other times our brains fill in the missing pieces.
optic nerve - the bundle of over one million
nerves fibers that carry visual messages from the retina to the brain.
peripheral vision - side vision, ability to see objects and movement outside of the direct line of vision.
photic - means of or relating to light.
photophores - a light-producing organ found especially in marine fishes that emits light from specialized structures or derives light from symbiotic luminescent bacteria.
photoreceptor - a nerve ending, cell, or group of cells specialized to sense or receive light. In the eye there are two types of photoreceptors - Rods and Cones.
pictograph - a symbol which is represented by a picture or image.
presbyopia - the gradual loss of the eye's ability to change focus (accommodation) for seeing near objects caused by the lens becoming less elastic, it is associated with aging and can occur in almost all people over age 45.
principles of design - are the use of the elements of design to construct an artwork. Some of these are: space, light, rhythm, perspective, balance, pattern, symmetry and harmony.
pupil - the opening in the iris which permits entry of light into eye. Through the opening and closing of the iris muscles excessive light is prevented from falling on the retina and damaging it by excess bleaching of the photoreceptors. Within the animal kingdom there are many weird and wonderful variations on pupil shape.
refraction - the bending of light rays when
passing through air, water, glass etc.
The angle of entry is significantly different to the angle of exit as the light
ray passes through the mediums of different density.
retina - the light-sensitive layer of tissue that lines the back of the eyeball, which sends visual messages through the optic nerve to the brain. Photoreceptors are found in the retina
retinomotor activity - The active movement of retinal components - photoreceptors and visual pigments within the retinal layers
rods - one type of specialized light-sensitive cells (photoreceptors) in the retina that provide peripheral vision and the ability to see objects in dim light, used extensively for night vision. The rods lie outside the fovea in the more peripheral parts of the retina. Most nocturnal animals rely solely on the use of rods for their vision (also see cones) as this allows them to perceive as much as possible visual information in conditions of low illumination.
sclera - The tough, white, outer layer of the eyeball which in conjunction with the cornea protects the entire eyeball.
scraffito - a technique where the surface is scratched in an artistic design.
spectrum - the distribution of energy emitted by a radiant source, as by an incandescent body, arranged in order of wavelengths. Often seen as a rainbow effect of coloured light.
species - A group of related organisms that are capable of breeding with each other to produce fertile offspring but are not capable of breeding with members of other species.
spectacle - is an additional clear covering that overlays the cornea, protecting the eye slit from silt and other abrasive materials. Occurs in bottom dwelling fish and those that live in shallow waters.
spherical aberration - the non-convergence of rays from one point of focus when passing through a spherical body, produces a scattering effect on the light ray.
stereo vision - visual perception of or exhibition in three dimensions.
stimulus - something that rouses or evokes a physiological response, or a specific functional reaction in organ or tissue.
strabismus - an abnormal condition in which the eyes do not move together or are "crossed". Due to this condition, both eyes do not always aim simultaneously at the same object. This results in a partial or total loss of stereo vision and binocular depth perception.
suspensory ligaments - elastic-like structures present in the eye that suspend the lens and pull it into shape for focusing distant objects onto the retina (see also accommodation).
symmetry - exact mirroring of form, shape, detail
on opposite sides of an object (i.e. - along its horizontal axis, both sides
look to be the same).
tapeteum - reflecting layer of vertebrate choroid
(it is the retina in some teleost (bony) fish), especially in nocturnal
forms and deep water fish. Generally contains guanine crystals reflecting light
back through the retina, increasing amount of light entering the eye, however
reducing the visual acuity.
vascular system - vessels that carry or circulate fluids, such as blood, lymph through the body of an animal.
vasoconstrictor - a nerve or drug, that causes constriction of a blood vessel.
ventral - describes the lower abdominal region of an organism
Victor Vasarely - Leader of the Op Art movement who created hard-edged optical tonal and colour optical art work. His work still influences art movements today.
vision - the act of perceiving and interpreting visual information with the eyes, mind, and body.
vision therapy - physical therapy for the visual system which includes the brain and eyes. Through a series of progressive eye exercises, patients develop or can recover normal visual skills.
visual acuity - the ability to distinguish details and shapes of objects, also called central vision.
visual field - the entire area that can be seen when the eye is forward, including peripheral vision.
visual pigment - are vital for colour vision. The eye's colour photoreceptor - the cone , can perceive color because of a light sensitive pigment they contain. This pigment is sensitive over a range of wavelengths (different colours of light have different wavelengths). Genes are responsible for the coding instructions to make these pigments, and if the coding instructions are wrong, then the wrong pigments are produced, and the cones will be sensitive to different wavelengths of light (resulting in a color deficiency or colourblindness).
vitreous humour - is the transparent, colorless
mass of gel that lies behind lens and in front of retina. The spherical shape
of the eyeball is maintained by this jelly-like substance.
wavelength - the distance between one peak or crest of a wave of light, heat, or other energy and the next corresponding peak or crest. Light for example is measured in nanometers and when all light wavelengths are put in progressive order a rainbow coloured spectrum results.