Spasm of accommodation
Encyclopedia
A spasm of accommodation (also known as an accommodation, or accommodative spasm) is a condition in which the ciliary muscle
Ciliary muscle
The ciliary muscle is a ring of striated smooth muscle in the eye's middle layer that controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humour into Schlemm's canal. It changes the shape of the lens within the eye not the size of the pupil which is...

 of the eye
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...

 remains in a constant state of contraction
Muscle contraction
Muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten, or remain the same...

. Normally, this contraction bends the 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...

 to allow the eye to "accommodate" for near-vision. However in a state of perpetual contraction, the ciliary muscle cannot relax when viewing distant objects. This causes vision to blur when attempting to view objects from a distance. This may be caused by pseudomyopia
Pseudomyopia
Pseudomyopia refers to an intermittent and temporary shift in refraction of the eye towards myopia, in which the focusing of light in front of the retina is due to a transient spasm of the ciliary muscle causing an increase in the refractive power of the eye...

 or latent hyperopia.

Although antimuscarinic drops can be applied topical
Topical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...

ly to relax the muscle, excessive pupil dilation may occur as an unwanted side effect. The dilation may pose a problem since it could allow an increased amount of harmful ultraviolet light to enter and damage the eye.

Patients who have accommodative spasm may benefit from being given a small plus prescription or through vision therapy
Vision therapy
Vision therapy, also known as visual training, vision training, or visual therapy, is a broad group of techniques aimed at correcting and improving binocular, oculomotor, visual processing, and perceptual disorders."-Historical development:...

.

Possible clinical findings include:

Normal Amplitude of accommodation
Amplitude of accommodation
Amplitude of accommodation is a measurement of the eye’s ability to focus clearly on objects at near distances . This eye focusing range for a child is usually about 5–7.5 cm . For a young adult, it is 10–15 cm . The focus range for a 45-year-old adult is about 50 cm...

 and Near point of convergence

Reduced Negative relative accommodation
Negative relative accommodation
Negative 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...



Difficulty clearing plus on facility testing
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