Within a healthy eye, the focusing system (accommodation) is what actively maintains the clarity of vision. When a person looks in the distance, the focusing system should be relaxed. When a person looks up close, the eye has to work to focus the image, like an auto-focus camera. Normally, switching between distance and near targets is effortless. Also, it should be easy to sustain focus at near for extended periods of time.
Eye focusing is developed rather well by age three and further accuracy is achieved throughout the early years of development. This function deteriorates with age, causing the need for bifocals and/or reading glasses beginning at about age forty. In individuals younger than forty, the eye focusing system should be very robust and have plenty of reserves of energy and ability to function well.
The eye focusing system can develop problems…
- Unable to sustain focus at near (accommodative insufficiency)
- Inability to switch easily from near to far and back to near (accommodative infacility)
- Over-focusing for near (accommodative spasm)
Sometimes, especially in children, eye focusing difficulties can present as any of the following symptoms:
- Excessive time completing assignments
- Excessive time copying from the board
- Reduced comprehension when reading
- SLOW reading speed
- Poor attention for near work
- Avoiding close work
- Blurring of print
- Headaches and fatigue
- Eyes “hurt” or “tired”
- Reading slowly
Efficient academic and athletic performance depends on the ability to focus the eyes rapidly and automatically to make images clear. Activities such as reading and writing require the ability to maintain prolonged focus up close. Copying from the board requires a change in focus that is rapid and efficient. Eye focusing is also intimately related to the ability to pay attention, especially for near tasks! Deficiencies in eye focusing are not a problem with the eye itself, but with the brain’s control of the eye focusing system. The neurological system that controls the eye focusing system may be uncoordinated or have simply ‘forgotten’ how to function correctly. Poor eye focusing skills can sometimes be a result of stress, either psychological stress or as a result of visual stress caused by excessive near work.
To learn about treatment options for eye focusing, click here.