It is one of the situations that baffles patients the most. They pass the eye test, read the bottom line of the chart without difficulty with each eye separately, are told that their eyesight is fine, and yet they still have a headache at the end of the day, skip lines when reading or notice that the letters start to blur together after a while.<\/p>\n
The explanation usually lies in something that this test does not measure. Visual acuity assesses how much each eye can see. Binocular vision assesses how the two eyes work together.<\/p>\n
What exactly is binocular vision?<\/strong><\/p>\n Our eyes capture two slightly different images and the brain merges them into a single image, with depth and three-dimensionality. For this process to work, both eyes must be aimed at the same point, focus in a coordinated manner and sustain that effort for as long as necessary.<\/p>\n When that coordination fails, visual acuity may still be perfect. What emerges is a set of symptoms that is rarely attributed to eyesight.<\/p>\n Symptoms that often go unnoticed<\/strong><\/p>\n In childhood, this has an added consequence: a child with a binocular vision problem does not say they have poor vision, because they have always seen this way. Instead, they avoid reading, tire more quickly than their peers or become distracted. And the problem ends up being interpreted as a behavioural or performance issue.<\/p>\n How it is assessed<\/strong><\/p>\n The assessment of binocular vision requires specific tests that are not part of a routine eye examination: assessment of eye alignment in different gaze positions, measurement of the near point of convergence, assessment of vergence reserves, evaluation of the relationship between accommodation and convergence, and measurement of stereopsis, which is the ability to perceive depth.<\/p>\n At INOF, this assessment is supplemented by objective recording of eye movement, which allows us to document how the eyes actually behave whilst reading or tracking an object, rather than relying solely on the patient\u2019s account.<\/p>\n What treatment is available<\/strong><\/p>\n It depends on the findings. It may be resolved with appropriate optical correction, with prisms incorporated into spectacles, with a visual therapy programme aimed at training coordination and the ability to sustain visual effort, or, where there is an underlying structural deviation, with treatment of the underlying strabismus.<\/p>\n It is important that the diagnosis is accurate before a decision is made, because the correct treatments applied to incorrect diagnoses will not work.<\/p>\n","protected":false},"excerpt":{"rendered":" It is one of the situations that baffles patients the most. They pass the eye test, read the bottom line of the chart without difficulty with each eye separately, are told that their eyesight is fine, and yet they still have a headache at the end of the day, skip lines when reading or notice…<\/p>\n","protected":false},"author":7,"featured_media":6191,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_joinchat":[],"footnotes":""},"categories":[147],"tags":[],"post_series":[],"class_list":["post-6220","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ocular-pathology-en","entry","has-media"],"yoast_head":"\n\n