Although you may not at first consider how Parkinson's disease can affect your eyes and vision, eye problems often are a symptom of the disease. While vision problems may be a side effect of medications you take for your Parkinson's, other eye and vision problems stem from muscle spasms, impaired ability to perform involuntary movements like blinking, cognitive impairment, or difficulty moving your eyes together – all symptoms of the disease and can lead to a need for vision correction.

If you have Parkinson's disease, regular eye exams can help identify symptoms related to your eyes or vision. Your eye care professional will discuss any treatment available for your particular problem.

Blepharospasm. Involuntary muscle contractions are one of the symptoms of Parkinson's disease. Blepharospasm is a condition characterized by involuntary spasms that cause your eyelids to blink excessively. Although there is no cure for eyelid twitching, there are treatments available to reduce the severity. Your eye doctor may recommend Botox injections near the eye to temporarily paralyze the muscles.  

Double Vision. Impaired eye-hand coordination and fatigue of eye muscles associated with Parkinson's disease can cause double vision, especially when you are moving your eyes from side to side. This can make it difficult to read. Although Parkinson's medications can help, so can resting your eyes throughout the day.

Blurred Vision. The side effects of some drugs to treat Parkinson's disease – particularly anticholinergics – include difficulty in focusing the eyes. Problems often occur when you first begin taking the drugs but then improve over time. However, taking the drugs for an extended period can cause blurred vision and may require reducing the dosage.

Visuo-Spatial/Depth Perception Deficits. Parkinson's disease can affect a person's perception as well as his or her motor functioning. While the findings of recent studies show that individuals with Parkinson's disease can experience visuo-spatial problems if disease-associated cognitive decline occurs, the exact cause isn't entirely known. Visuo-spatial impairment can cause problems with accurately judging speed and the distance between objects.

Visual Hallucinations. Some people with Parkinson's disease experience visual hallucinations due to impaired visual processing rather than psychosis. Treatment for visual hallucinations may include improving visual acuity (e.g., treating presbyopia or other refractive errors), improving your visual perception with adequate lighting, or adjusting your anti-Parkinson medications, which may cause hallucinations as a side effect.

Slow, Jerky Eye Movements. When working on near tasks, the slowness of eye movements often associated with Parkinson's disease can cause eyestrain, double vision, and headaches. The inability to move the eyes quickly results in slow, jerky motions, which can make certain activities – including driving – difficult. Medications to treat Parkinson's tremors and muscle spasms can make the condition worse.

Dry Eyes. Blinking less decreases tear production, which can lead to blurred vision, increased sensitivity to light, and difficulty driving at night. Dry eyes also increase the risk of eye infections.

Decreased blinking in Parkinson's disease is associated with reduced production of the chemical dopamine. When nerve cells in the brain die, they produce less dopamine, which leads to impaired movement. Movement problems may include slow voluntary movements, decrease in involuntary movements, and a mask-like facial expression in some people.

If you suffer from chronic dry eye, your eye doctor may recommend the use of over-the-counter artificial tears to lubricate the eyes. Depending on the severity of the condition, you may need steroid eye drops or prescription eye drops that increase tear production.