The report attributes this growth outlook to an increase in the geriatric population and the subsequent rise in prevalence of Asthenopia
They postulated that headaches observed are due to associated contraction of the scalp muscles.6 Medical term for headache associated with eye strain or fatigue is asthenopia
, which is thought to be triggered by ametropia, extra ocular muscle imbalance, improper reading or working environment and inaccurate reading or working habits.7 Another meta-analysis on the subject including 2465 subjects revealed that majority of children with asthenopia
had no refractive error and estimated a pooled prevalence of ametropia of 19.7% in children.8 Ophthalmologists are frequently referred cases for evaluation of refractive errors and diagnose ocular causes of headache.
Low NRA, excess/ spasm accommodative esophoria at near function causing asthenopia
at near, variable near and distance vision blur Accommodative Slow accommodation LowAF, low PRA and NRA infacility response when switching from near to far focus and back, commonly presents as distance blur when looking up from reading Convergence Difficulty EXOP at near, reduced insufficiency converging the eyes PRV at near, receded for near focus NPC, low BO VF.
Prevalence of Asthenopia
and risk factors in Chinese collage students.
Eye strain (asthenopia
) is a symptom complex that involves sensations of irritation to the eye itself, changes in vision (such as blurred or double vision), and associated symptoms such as headache7.
The control of the deviation is commonly indirectly deduced during the follow-up from signs like degraded stereopsis, onset of amblyopia, increased deviation, or symptoms like asthenopia
, visual discomfort, and diplopia, even if in IXT suppression usually protects from diplopia.
The survey of the subjective questionnaire showed that the dry eye symptom was more remarkable after orthokeratology (P = 0.03), nevertheless the feeling of asthenopia
was relieved (P = 0.01).
Engle, "Is all asthenopia
the same?," Optometry and Vision Science, vol.
2005 investigated the efficacy of natural astaxanthin on speed of accommodation (the ability for the eye to change focus from near plane of focus to a far plane of focus and vice versa) in 40 healthy individuals who had asthenopia
It is now an accepted fact that stereoscopic images (3-D images) cause an "intense eye accommodation activity"7 such as headaches, nausea, blurred vision, diplopia, asthenopia
and visually-induced motion sickness(VIMS), which is characterised by tiredness, headache and soreness of the eye,8,9 collectively known as the 3-D vision syndrome.8,9 The phenomenon of the 3-D vision syndrome has been strengthened by researches conducted in Rome, Italy.
There is much evidence suggesting that illumination of the environment is a modifying factor forocular status [2, 3, 6], visual asthenopia
[25, 28], and the contrast modulation of visual cortical cells [29, 30].