Blepharospasm may be defined as involuntary tight contraction of the eyelids.
That this term concerns the eyelids is indicated by the prefix "blephar-" which refers to the eyelid. The suffix "-spasm" refers to tight muscle contraction.
The formal definition above may be less easy for the layman to relate to than equivalent but more colloquial descriptions such as a blepharospasm being any abnormal tic or twitch of the eyelid. (Technically a "tic" is a sudden, repetitive, nonrhythmic, motor movement of particular muscle groups. Many people will also be familiar with the apperance of someone having and uncontrolled tic or twitch, especially if visible areas such as the face or neck are involved.)
Typical symptoms and effects involving blepharospasm include:
- Spasms of eye closure - typically in situations of bright light, or when concentrating, e.g. on reading or watching television
- Tiredness, irritation, or other emotional tensions can exacerbate the symptoms
- Awareness of being observed may reduce symptoms, or their frequency
- Symptoms generally occur during active/waking hours, rather than overnight.
- If the blepharospasm progresses (gets worse), the spasms happen more frequently - making tasks difficult, and in extreme cases perhaps even making it very difficult for the patient to see at all.
Many cases of blepharospasm occur arising spontaneously or from an obscure or unknown cause. Such cases are called either benign essential blepharospasm or primary blepharospasm.
Conversely, cases of blepharospasm due to a specific known organic disease are known generically as secondary blepharospasm.
Examples of diseases that include or may lead to secondary blepharospasm include:
More about Ophthalmology:
This section includes short definitions
of many diseases, disorders, and conditions of the eyes and visual system.
For definitions of other terms in this category, choose from the list to the left (but note that this is not a complete/exhaustive list).
Other related pages include
- A diagram of the eye
- Definitions and descriptions of the parts of the eye
- A concise description of the human retina
- Definitions of parts of the retina
- Clinical and surgical procedures re. eyes and human visual system
For further information see also our pages of books about ophthalmology.