This article presents a model for understanding the development of visual perception from a dynamic systems theory perspective. It contrasts to a hierarchical or reductionist model that is often found in the occupational therapy literature. In this proposed model vision and ocular motor abilities are not foundational to perception, they are seen…

In the "The Science Study Series" book "The Physics of Television", it is stated that persistence of vision lasts for about a tenth of a second. This will be a notional figure just as 25 cm is taken to be the least distance of distinct vision. Estimates range from 1/8 to 1/16 s.

Insect vision is an area of active research that allows fruitful exploration into the nature of the scientific endeavor because of the bias our own vision brings. As scientists, we use our senses to make observations, but we can't assume that what we see is what insects see; we are forced to think outside of our own senses when we ask questions…

Historically, the bodily senses have often been regarded as impeccable sources of spatial information and as being the teacher of vision. Here, the authors report that the haptic perception of slope by means of the foot is greatly exaggerated. The exaggeration is present in verbal as well as proprioceptive judgments. It is shown that this…

The paper presents a unique approach in associating perspective projection with the image beheld by the eye and demonstrates that all graphical and photographic perspective projections must contain distortion when compared to the image beheld by the eye. (Contains 8 figures.)

This article explores the importance of vision in dance from both the teacher's and the learner's perspectives. Since vision does not function in isolation, the interplay between sight and other modes of learning movement-based material is considered as well. Movement activities are provided to assist with understanding this information…

Neuroscience research provides new models for understanding vision that challenge Betty Edwards' (1979, 1989, 1999) assumptions about right brain vision and common conventions of "realistic" drawing. Enlisting PET and fMRI technology, neuroscience documents how the brains of normal adults respond to images of recognizable objects and scenes.…

Some visual processing deficits in developmental dyslexia have been attributed to abnormalities in the subcortical M stream and/or the cortical dorsal stream of the visual pathways. The nature of the relationship between these visual deficits and reading is unknown. The purpose of the present article was to characterize reading-related perceptual…

Choroidal neovascularization is a rare condition where aberrant blood vessels behind the retina grow and then bleed, eventually becoming blind areas called Fuchs' spots. A woman suffering from this rare eye disease speaks about the challenges of coping with the visual disability and her determination to make the best of what life has to offer.

A fly is buzzing around in the kitchen. You sneak up on it with a flyswatter, but just as you get close to it, it flies away. What makes flies and other insects so good at escaping from danger? The fact that insects have eyesight that can easily detect moving objects is one of the things that help them survive. In this month's Science Shorts,…

The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands,…

Discusses the role of theoretical knowledge in seeing and makes the case that direct and indirect forms of cognitive perception are pervasive forms of seeing in educational practice, and that both forms are fundamentally theory laden. Suggests that theoretical knowledge enhances our capacity to see in practice. (SLD)

Describes subjective-contour illusions and gives explanations for perception of shape and brightness in these figures. Supports cognitive mechanisms rather than psychological mechanisms. Gives examples of subjective-contour illusions and summarizes explanations of other psychologists with regard to this topic. (CW)

Many simple experiments can be performed in the classroom to explore the physics of vision. Students can learn of the two types of receptive cells (rods and cones), their distribution on the retina and the existence of the blind spot.

In this article, we detail how to produce two inexpensive micromanipulators that offer high precision (approximately 25 micrometers) along a single axis of movement. The more expensive of the designs provides improved versatility along multiple axes. Both manipulators offer substantial savings over commercially available micromanipulators with…