Published: · Last updated: · Publisher: Smart Vision Optometry
At a glance: Light is focused onto the retina, where cells convert it into signals sent to the brain. Vision involves both the eyes and brain; an optometric assessment examines defined visual functions rather than diagnosing every learning or neurological condition.
How the Eyes and Brain Create Vision
Vision begins when light enters the eye and is focused onto the retina. Photoreceptor cells in the retina convert light into electrical signals, which travel through the optic nerve to the brain. The US National Eye Institute explains this pathway in its guide to how the eyes work.
Seeing is not the work of the eyes alone. The brain processes the incoming signals and combines them with attention, movement, memory and other information so that we can recognise objects, judge position and respond to what is around us.
From the Retina to Visual Processing
Retina and Optic Nerve
Rods and cones are photoreceptors in the retina. They contribute to vision under different lighting conditions and to colour and detail. Retinal cells process these signals before the optic nerve carries visual information towards the brain.
Visual Cortex and Connected Brain Regions
Visual information reaches the visual cortex at the back of the brain and is processed through connected pathways. These pathways support features such as form, colour, motion and spatial location. Visual perception is distributed across networks rather than being produced by a single lobe acting alone.
Attention, Recognition and Spatial Awareness
Other brain networks help direct attention, recognise familiar objects and faces, use visual memory and coordinate visually guided actions. This is why clear eyesight and visual processing are related but are not identical concepts. Our supervised visual-perception example illustrates an immediate response to altered visual information, with clear limits on what that example can show.
What an Optometric Assessment Can Examine
An optometric assessment can examine visual acuity, refractive error and eye health. Depending on the person’s history and symptoms, it may also assess focusing, eye alignment, binocular coordination and eye movements.
These findings need to be interpreted in context. An eye examination is not a general test of brain function and does not diagnose dyslexia, ADHD or other developmental and learning conditions. Referral to another health or education professional may be appropriate when symptoms extend beyond the scope of optometry.
Vision therapy may be discussed for selected, diagnosed visual conditions after an individual assessment; it is not required for every patient and outcomes vary. The RANZCO position statement on learning difficulties in children explains that primary learning difficulties are not caused by eye or vision problems and should not be treated as though they are.
Discuss Visual Symptoms with Smart Vision Optometry
If you notice persistent blur, double vision, eye strain or difficulty coordinating the eyes, an examination can help identify whether an eye-health, refractive, focusing or binocular-vision issue is present. The appropriate assessment and management depend on the individual findings.
For information about Smart Vision Optometry’s services, visit the main website. Related information is also available from Myopia Prevention Sydney and Orthokeratology Sydney.
Book an appointment, or call the Bondi clinic on (02) 9365 5047 or the Mosman clinic on (02) 9969 1600 to discuss the most appropriate starting assessment.
Frequently asked questions
How does information travel from the eye to the brain?
Cells in the retina convert light into electrical signals. Those signals travel through the optic nerve to the brain.
Is visual acuity the same as all visual processing?
No. Visual acuity is one aspect of vision. Visual perception also involves how incoming information is processed and used.
Can an eye examination diagnose dyslexia or ADHD?
An eye examination does not diagnose dyslexia or ADHD. Where concerns extend beyond optometry, assessment by the appropriate health or education professional may be needed.
