Eye Perception

Visual perception refers to a set of skills used to collect and interpret visual information taken in from our environment. The visual information gathered is combined with our other senses, allowing us to derive meaning from what we see. Through the process of merging visual data with our other senses, we are also able to organize eye and physical movement. For this, visual perception is critical when it comes to our ability to learn, move with ease and understand the world around us.

How Your Eyes See

Seeing begins with the lens of the eye focusing an image onto the retina, a light-sensitive membrane located in the rear of the eye. The retina contains cells called photoreceptors, and they translate light into electrochemical signals that journey along the optic nerve fibers to the brain. When the signals reach the brain, they are read as vision in the visual cortex and the brain puts meaning to what is being seen.

Just as the eyes send signals to the brain, the brain also sends signals to the eyes, ultimately controlling their movement. And as we are aware, the brain additionally releases signals to other organs, muscles and nerves throughout the body, controlling their movement as well.

When our vision is not in sync with our brain and other senses, there is a dysfunction, and this can lead to:

  • Being easily distracted or having a short attention span
  • Lack of concentration
  • Difficulty understanding and following instructions
  • The inability to recall a sequence of letters, numbers or objects in the order they were initially presented
  • The inability to recognize visual clues
  • Clumsiness
  • Trouble with rhythm
  • Struggles with learning left and right
  • Reordering numbers or letters when copying or writing
  • Complications learning the alphabet or recognizing words

Correcting Your Vision With Therapy

Through the aid of visual therapy, this dysfunction can be corrected with a mix of vision exercises and specialized equipment that train the visual system to work in coordination with the brain and other senses.

Devices used to help achieve this may include:

  • Therapeutic or corrective lenses
  • Balance boards
  • Computer software
  • Vision-motor-sensory training equipment
  • Electronic target with programmed apparatuses
  • Optical filters
  • Prisms
  • Occluders or eye patches

Therapy is guided by an optometrist and is performed in an office once to twice a week for up to an hour. The types of exercises and equipment, as well as the number of sessions required, will depend on the individual needs of the patient. To supplement office visits, the optometrist will likely give the patient instruction on how to perform certain vision exercises at home.

Following the completion of vision therapy—meaning all necessary sessions have ended—the individual should be able to coordinate eye and physical movements, their visual capabilities should have improved and there should be greater efficiency when it comes to processing and interpreting visual information.

Eye Focusing

The eyes have a focusing system called accommodation; it allows for visual clarity. The system is rested when you look at an object that is far away and is not forced to strain like it would if the target were close. In normal circumstances, the eyes are able to effortlessly transition between objects that are far and near, and can sustain focus on items that are close, despite the added effort it places on the focusing system.

Problems With Focusing

However, if a problem arises with the system, the eyes have trouble focusing on objects that are nearby (accommodative insufficiency) or switching attention between targets that are far and near (accommodative infacility). They may also excessively focus on objects that are close (accommodative spasm). As a result of any of these impediments, the person may have blurry vision, diminished comprehension when reading, headaches, eye pain, eye fatigue, slow reading speed and trouble concentrating while performing tasks. All can affect a person’s academic capabilities or ability to perform daily tasks.

Often when issues with the eye focusing system develops, they are not related to the eyes themselves. Instead, they can be related to the brain’s inability to regulate the system because the neurological system has somehow been compromised. Poor eye focus could also transpire due to psychological or visual stress.

Correcting the Problem

Vision therapy can help, as it is a type of physical therapy for both the eyes and brain, and aims to train the visual system to correct itself. This non-surgical approach helps by using a combination of vision exercises and equipment to specifically target eye focusing problems that inhibit learning, reading and education. It also reduces eye strain.

Performed under the supervision of a vision therapy specialist, the exercises—which are conducted in an office up to twice a week for 30 minutes to an hour—are made to fit the individual needs of the patient. Some visual training workouts can also be done at home and are used to supplement in-office visits.

Equipment that may be used during a vision therapy session includes:

  • Prisms
  • Corrective or therapeutic lenses
  • Eye patches or occluders
  • Optical filters
  • Computer software
  • Electronic target with programmed mechanisms
  • Balance boards
  • Visual-motor-sensory training devices

The number of sessions depend on the severity of the eye focusing problem, as well as the associating symptoms (e.g. slow reading speed or blurry vision). Over time, vision therapy should improve essential visual skills and capabilities, enhance visual efficiency, and alter how the patient processes and understands visual information.

Eye Coordination

Each eye picks up a slightly different image, but through a process called fusion, the brain blends the images together to make one three-dimensional picture. Good eye coordination is needed, however, and allows the eyes to sustain proper alignment so that they can focus on practically the same image, though it is seen somewhat differently.

Causes of Poor Eye Coordination

For some, eye coordination is poor. It may be the result of immature eye muscle control or a defect in vision development. Because of this, the person must apply excessive force to try to keep the eyes aligned. Should poor eye muscle control be severe enough, the muscles cannot adjust the eyes enough for them to capture the same image, and double vision may be the outcome.

With double vision, the eyes and brain pick up two different images. To make up for this imbalance, the brain overlooks the visual it gets from the weaker, more impaired eye. And just like any body part that is not being used, its functions deteriorate. Thus, with the weaker eye no longer being depended upon for use, permanent visual impairment sets in. This can lead to a condition known as lazy eye or amblyopia, and signs of poor eye coordination may persist, including:

  • Difficulty reading and/or concentrating
  • Vertigo
  • Eye fatigue
  • Headaches
  • Poor performance of tasks

Vision therapy is one type of treatment used to assist with the correction of eye coordination problems. This form of physical therapy uses a mixture of vision exercises and specialized equipment to train the visual system to repair itself and reduce eye strain.

Treatment Options

Implemented under the guidance of an optometrist, vision therapy is performed in an office once to twice a week for up to an hour. Depending on the severity of the eye coordination problem and associated symptoms, the types of exercises and equipment will be tailored to meet the individual needs of the patient. These factors will also determine the number of sessions the patient requires. To complement in-house visits, the optometrist may also instruct the patient on how to perform certain vision exercises at home.

Devices that may be used during a vision therapy session include:

  • Therapeutic or corrective lenses
  • Optical filters
  • Prisms
  • Occluders or eye patches
  • Balance boards
  • Computer software
  • Vision-motor-sensory training equipment
  • Electronic target with programmed apparatuses

When vision therapy is complete, and all necessary sessions have ended, the patient’s visual skills and capabilities should have improved and symptoms should have decreased significantly. In addition, visual efficiency should have enhanced and the patient should be more efficient when it comes to processing and understanding visual information.

Eye Movement

Eye movement refers to the voluntary and involuntary movements of the eyes that assist with obtaining, fixating and following visual stimuli. The eyes are each connected to a system of six muscles. Light is sensed by the retina, which is a type of tissue that contains cells known as photoreceptors. These cells translate light into electrochemical signals that move along the optic nerve fibers to the brain. Once they reach the brain, the signals are interpreted as vision in the visual cortex and the brain applies meaning to what is being seen.

How Your Eyes Interpret Movement

And just as the eyes send signals to the brain, the brain sends signals to the eyes. Three cranial nerves transport signals from the brain to the muscles attached to each eye. This ultimately controls both voluntary and involuntary eye movements.

There are four types of eye movement:

  • Saccades – rapid, flying movements of the eyes that suddenly change the point of fixation. These movements range in scale from the tiny movements made while reading to greater movements made while scanning a room
  • Vergence movements – these movements bring into the line the area of the retina (fovea) designed for high perception
  • Smooth pursuit movements – steady tracking movements that are meant to keep moving stimulus in focus
  • Vestibulo-ocular movements – helps stabilize the eyes when the head’s position moves

Poor eye muscle control or injury/trauma can affect the eyes’ ability to move in harmony, leading to eye movement disorders like:

  • Nystagmus – fast, uncontrollable movements of the eyes. This can sometimes be referred to as dancing eyes
  • Strabismus – the eyes are misaligned and not aimed in the same direction. This may cause crossed eyes or other vision problems like lazy eye

Correcting Eye Movement Problems

If an individual has problems with eye movement, vision therapy is one treatment that can help by using vision exercises and specialized equipment to strengthen the eye muscles, leading to more fluid, cooperated eye movement.

Performed under the guidance of an optometrist, vision therapy is conducted in an office setting up to twice a week for an hour. The types of exercises and equipment will be tailored to meet the individual needs of the patient and are based on the severity of the eye movement problem, as well as any associated symptoms. These influences will also establish the number of sessions the patient requires. To accompany in-house visits, the optometrist may also instruct the patient on how to perform certain vision exercises at home.

Equipment that may be used during a vision therapy session includes:

  • Therapeutic or corrective lenses
  • Optical filters
  • Prisms
  • Occluders or eye patches
  • Balance boards
  • Computer software
  • Vision-motor-sensory training equipment
  • Electronic target with programmed apparatuses

When vision therapy is over, and all necessary sessions have concluded, the patient should be able to perform the four types of eye movement with greater ease and should be more efficient when it comes to processing and interpreting visual information.