Study of Visual Acuity during the Ocular Pursuit of Moving Test Objects I Introduction*

Stimulus determinants of dynamic visual acuity: I. Background and exploratory data.

“…There is general agreement that acuity for a moving target decreases as a function of the target's angular velocity with respect to the observer. This result has been obtained for tai-et movement in a horizontal direction (3,4), a vertical direction (5,6), and in a circ.lar path on a plane tangent to the observer's line of sight (7,8). Similar results are obtained when the observer moves with respect to a stationary target; for example, or.…”

“…The relationship between DVA and static acuity is not entirely clear. It appears that there are large individual differences in DVA among subjects whose static visual acuitim are similar (4,25), and that any correlation between the two is increased when using lower DVA target speeds, binocular viewing conditions, longer e:.posure times, and free head movement (30,(21)(22)(23).…”

“…The major attempt at a quantitative description of the DVA function is represented in the early work of Ludvigh and Miller (3,4). Using group data, they determined the best empirical fit to a polynominal of the form y = a + bxr, where y = target size in minutes of arc, y target angular velocity in degrees per second, n is a positive integer which was determined empirically to equal 3, and a and b are parameters to be determined by curve fitting ,) data, using the method of moments.…”

Antihistamines and visual function: studies on dynamic acuity and the pupillary response to light.

“…Dynamic visual acuity was the term used by Ludvigh & Miller (1958) to describe the ability of an individual to perceive detail in moving targets during ocular pursuit. It is not a fundamental visual attribute, but it depends on the sensory and motor components of the ocular response, together with the feedback systems which link them.…”

Oculomotor and linguistic processing effects in reading dynamic horizontally scrolling text.

“…Following a moving object in this way reduces blurring of the target across the retinal image, meaning that, at least at a stimulus velocity allowing for a comparable reading rate as for static text (around 250wpm; Rayner, 1998), dynamic visual acuity is comparable to that for static targets (Ludvigh & Miller, 1958). These pursuit periods are clearly distinct from standard fixations that are made in reading, as the eye is not stationary but rather moving throughout; however, for simplicity, we will hereafter refer to them as fixations, reflecting their similar functional role.…”