Search results
Results from the WOW.Com Content Network
Light from a single point of a distant object and light from a single point of a near object being brought to a focus. The accommodation reflex (or accommodation-convergence reflex) is a reflex action of the eye, in response to focusing on a near object, then looking at a distant object (and vice versa), comprising coordinated changes in vergence, lens shape (accommodation) and pupil size.
Fear-potentiated startle (FPS) is a reflexive physiological reaction to a presented stimulus, and is an indicator of the fear reaction in an organism. The FPS response can be elicited in the face of any threatening stimulus (e.g., any object, person or situation that would cause someone to experience feelings of fear), but it can also be elicited by a neutral stimulus as a result of fear ...
Incorrect vergence response can cause double vision. Accommodation is the eye’s focusing mechanism and it is engaged to produce a sharp image on a retina. Both of these mechanisms are neurally linked forming the accommodation-convergence reflex [1] of eyes.
Accommodation usually acts like a reflex, including part of the accommodation-convergence reflex, but it can also be consciously controlled. The main ways animals may change focus are: Changing the shape of the lens. Changing the position of the lens relative to the retina. Changing the axial length of the eyeball. Changing the shape of the cornea.
Bezold-Jarisch reflex — involves a variety of cardiovascular and neurological processes which cause hypopnea and bradycardia. Biceps reflex — a jerking of the forearm when the biceps brachii tendon is struck with a tendon hammer, stimulating the C5 and C6 reflex arcs. Blushing — a reddening of the face caused by embarrassment, shame, or ...
However, errors in this relationship can cause problems, such as hyperopic individuals having a tendency for crossed eyes because of the over exertion of their accommodation system. Clinically, accommodative convergence is measured as a ratio of convergence, measured in prism diopters, to accommodation, measured in diopters of near demand.
Usually the onset of the startle response is a startle reflex reaction. The startle reflex is a brainstem reflectory reaction (reflex) that serves to protect vulnerable parts, such as the back of the neck (whole-body startle) and the eyes (eyeblink) and facilitates escape from sudden stimuli. It is found across many different species ...
Accommodative excess may occur secondary to convergence insufficiency also. In convergence insufficiency near point of convergence will recede, and positive fusional vergence (PFV) will reduce. So, the patient uses excessive accommodation to stimulate accommodative convergence to overcome reduced PFV. [5]