Accommodative convergence
Encyclopedia
Accommodative convergence is that portion of the range of inward rotation of both eye
s (i.e. convergence
) that occurs in response to an increase in optical power
for focusing by the crystalline lens
(i.e. accommodation
).
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
s (i.e. convergence
Convergence (eye)
In ophthalmology, convergence is the simultaneous inward movement of both eyes toward each other, usually in an effort to maintain single binocular vision when viewing an object. This action is mediated by the medial rectus muscle, which is innervated by Cranial nerve III...
) that occurs in response to an increase in optical power
Optical power
Optical power is the degree to which a lens, mirror, or other optical system converges or diverges light. It is equal to the reciprocal of the focal length of the device. The dioptre is the most common unit of measurement of optical power...
for focusing by the crystalline lens
Lens (anatomy)
The crystalline lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina. The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a...
(i.e. accommodation
Accommodation (eye)
Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image on an object as its distance changes....
).
See also
- Convergence insufficiencyConvergence insufficiencyConvergence insufficiency or Convergence Disorder is a sensory and neuromuscular anomaly of the binocular vision system, characterized by an inability of the eyes to turn towards each other, or sustain convergence.-Symptoms:...
- DivergenceDivergence (eye)In ophthalmology, divergence is the simultaneous outward movement of both eyes away from each other, usually in an effort to maintain single binocular vision when viewing an object. It is a type of vergence eye movement.-References:...
- Negative relative accommodationNegative relative accommodationNegative relative accommodation was proposed by Prof. Joseph Kearney of Oxford University in 1967, is a measure of the maximum ability to relax accommodation while maintaining clear, single binocular vision. This measurement is typically obtained by an orthoptist, ophthalmologist or optometrist...
- Positive relative accommodationPositive relative accommodationPositive relative accommodation is a measure of the maximum ability to stimulate accommodation while maintaining clear, single binocular vision. This measurement is typically obtained by an orthoptist, ophthalmologist or optometrist during an eye examination using a phoropter...
- VergenceVergenceA vergence is the simultaneous movement of both eyes in opposite directions to obtain or maintain single binocular vision..When a creature with binocular vision looks at an object, the eyes must rotate around a vertical axis so that the projection of the image is in the centre of the retina in both...