Search results
Results from the WOW.Com Content Network
Horizontal optokinetic nystagmus. The optokinetic reflex ( OKR ), also referred to as the optokinetic response, or optokinetic nystagmus (OKN), is a compensatory reflex that supports visual image stabilization. [ 1] The purpose of OKR is to prevent image blur on the retina that would otherwise occur when an animal moves its head or navigates ...
Nystagmus. Nystagmus is a condition of involuntary (or voluntary, in some cases) [1] eye movement. [2] People can be born with it but more commonly acquire it in infancy or later in life. In many cases it may result in reduced or limited vision. [3] In normal eyesight, while the head rotates about an axis, distant visual images are sustained by ...
Seismic oceanography is a form of acoustic oceanography, in which sound waves are used to study the physical properties and dynamics of the ocean. It provides images of changes in the temperature and salinity of seawater. Unlike most oceanographic acoustic imaging methods, which use sound waves with frequencies greater than 10,000 Hz, seismic ...
Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters. Physical oceanography is one of several sub-domains into which oceanography is divided. Others include biological, chemical and geological oceanography.
Internal waves (marked with arrows), caused by tidal flow through the Strait of Gibraltar and made visible by sea surface roughness enhance sunlight backscatter. Internal waves are gravity waves that oscillate within a fluid medium, rather than on its surface. To exist, the fluid must be stratified: the density must change (continuously or ...
Ocean currents are primarily horizontal water movements. An ocean current flows for great distances and together they create the global conveyor belt, which plays a dominant role in determining the climate of many of Earth's regions. More specifically, ocean currents influence the temperature of the regions through which they travel.
Ocean stratification. Ocean stratification is the natural separation of an ocean's water into horizontal layers by density, which is generally stable because warm water floats on top of cold water, and heating is mostly from the sun, which reinforces that arrangement. Stratification is reduced by wind-forced mechanical mixing, but reinforced by ...
Positional alcohol nystagmus. Positional alcohol nystagmus (PAN) is nystagmus (visible jerkiness in eye movement) produced when the head is placed in a sideways position. PAN occurs when the specific gravity of the membrane space of the semicircular canals in the ear differs from the specific gravity of the fluid in the canals because of the ...