The use of technology is increasing on a daily basis, and with it, complaints of eye strain and blurry vision at near. Younger patients who struggle with their vision up close usually have what we refer to as an accommodative disorder. Older patients (over 40) will experience these symptoms as a normal aging process that we know as presbyopia.
The ability to pull your focus in to see at near requires the eye to change power by increasing the thickness and curvature of the lens inside the globe. This occurs when the muscle behind the iris (the ciliary muscle) contracts, loosening the fibrous strands that hold the lens taut inside the eye. When these changes happen, it enables the patient to see clearly up close. The lens inside the eye loses its elasticity with age which hinders the ability of older patients to maintain clear vision at near.
There are several different types of accommodative issues; however, the most common is known as accommodative insufficiency. This type of accommodative dysfunction is seen in about 60-80% of cases. It is also the most common type of accommodative problem seen in children between the ages of 8 and 11 years old. Correct diagnosis and treatment are key to improving this condition.
Patients with accommodative issues usually complain of difficulty performing close work. Their symptoms may include fatigue, double vision at near, and eyestrain, to name a few. This would clearly interfere with a student’s academic progression since the only way to relieve the visual strain is to avoid close work. Unfortunately, this condition is often overlooked in younger children. It is imperative that it not be confused with dyslexia or another binocular vision disorder.
Treatment includes in-office or home-based vision therapy to strengthen the ciliary muscle (think physical therapy) and cure rates are highly successful. Eighty to one hundred per cent of cases can be resolved with vision therapy. Magnifying lenses are also sometimes used, but care must be exercised as to the amount of magnification provided to the patient. A +1.00 pair of reading glasses may relieve the patient’s symptoms while still allowing the accommodative system to engage during near tasks; however a +2.00 pair of readers may not allow the accommodative system to work at all, thereby serving as a crutch for the patient. The possibility of long-term improvement in accommodative ability with the +2.00 lenses would be greatly reduced.
Vision therapy tasks are designed to increase the range of a patient’s accommodation through both stimulation as well as relaxation of the accommodative system. Improving the patient’s ability to quickly engage or relax the accommodative system is another goal of therapy. Each eye is strengthened individually at first, with binocular exercises coming later in therapy. In office therapy consists of weekly one hour sessions for 12 weeks, with four days a week of homework that is reevaluated at the following visit. Homework sessions are generally 30 minutes in length. Overall, results indicate the compliance with vision therapy produces better long term results than simply using reading glasses alone.
It’s important to understand that if undiagnosed, accommodative insufficiency can prevent students from reaching their academic potential. Vision therapy can help to improve this condition and should not be overlooked in deciding the best treatment option for these patients.