When People Talk About Parkinsons They May Mention The Effects It Has On The Substantia Nigra But Did You Know That There Are Other Areas Of The Brain That Are Affected By The Condition
Parkinson’s is a condition that causes the gradual loss of the dopamine-producing brain cells of the substantia nigra — an area of the brain located just above where the spinal cord meets the midbrain. It is these cells that produce and release the neurotransmitter dopamine, which has a key role in turning thought about movement into action.
While this definition of the condition is useful to briefly explain Parkinson’s, the whole story is somewhat more complex. Over the last 30 years, it has become accepted that Parkinson’s also causes a number of non-motor symptoms, such as changes in sleep, smell and even the way we think, which likely involve other areas of the brain.
Now scientists are looking at the broader effects of the condition on the brain in an attempt to better understand why people experience different symptoms. The finding could lead us to new treatments that tackle more than just the motor symptoms of the condition.
Eyekrafters Medical Optics Eye Clinic And Parkinsons And Vision Problems In South Plainfield New Jersey
Many eye diseases can be quickly and easily diagnosed during a comprehensive eye exam. If you were diagnosed with an eye disease, such as Cataracts, Glaucoma, Macular degeneration, Diabetic retinopathy, or Dry eye, you may be overwhelmed by the diagnosis and confused about what happens next. Will you need medications or surgery – now or in the future? Our South Plainfield eye doctor has prepared the following answers to your questions about eye disease.
Ocular And Visual Disorders In Parkinsons Disease: Common But Frequently Overlooked
This literature search covering 50 years reviews the range of ocular and visual disorders in patients with PD and classifies these according to anatomical structures of the visual pathway. It discusses six common disorders in more detail, reviews the effects of PD-related pharmacological and surgical treatments on visual function, and offers practical recommendations for clinical management.
Patients With Parkinson Disease At Increased Risk Of Vision Eye Issues Study Shows Matthew Gavidia
Patients with Parkinson disease were found to be more likely to experience vision and eye issues, such as blurry vision, dry eyes, trouble with depth perception, and problems adjusting to rapid changes in light, compared with people without the disorder, according to study findings.
Patients with Parkinson disease were found to be more likely to experience vision and eye issues, such as blurry vision, dry eyes, trouble with depth perception, and problems adjusting to rapid changes in light, compared with people without the disorder, according to study findings published in Neurology.
In patients with PD , irregular eyesight can prove a chief issue, as ophthalmologic disorders combined with postural and gait instability from the disorder may increase the risk of falls and fall-related injuries, noted the study authors.
Risk of vision impairment is potentially common for PwP because PD is linked with retinal dopamine depletion and decreased dopaminergic innervation of the visual cortex, which can lead to visual problems such as diminished oculomotor control, contrast sensitivity, color vision, and visuospatial construction. PwP are also at increased risk for seborrheic blepharitis and keratoconjunctivitis sicca .
In PwP with ophthalmologic symptoms, 68% reported that it interfered with daily activities, compared with 35% of controls .
Difficulty Moving The Eyes Or Difficulty In Focusing On Moving Objects
Difficulties moving the eyes up and down are more common in a condition called Progressive Supranuclear Palsy , a form of parkinsonism. If you experience this problem, your specialist or Parkinson’s nurse if you have one, will be able to give advice.
Caution! If detecting or seeing movement is difficult, particularly estimating the speed of a moving object such as a car, great care should be taken when out and about, both when driving and walking.
Vision Problems More Common In Patients With Parkinson Disease
This article, “Vision Problems May Be Common in Parkinson Disease,” was originally published on NeurologyLive.
Results of a new study have uncovered a link between the development of Parkinson disease and an increase in ophthalmologic symptoms that impact a patient’s day-to-day activities.
The study, which included 848 patients with Parkinson and 250 healthy controls, showed that 82% of those with disease had ?1 ophthalmologic symptom in comparison with 48% of the control group . Study author Carlijn D.J.M. Borm, MD, of Radboud University Medical Centre in Nijmegen, The Netherlands, and colleagues noted that screening questionnaires like the Visual Impairment in Parkinson’s Disease Questionnaire —which the study utilized—may aid in recognizing these vision problems, thus improving timely treatment.
“It is especially important for people with Parkinson’s to have the best vision possible because it can help compensate for movement problems caused by the disease, and help reduce the risk of falls,” Borm said in a statement. “Our study found not only that people with Parkinson’s disease had eye problems that go beyond the aging process, we also found those problems may interfere with their daily lives. Yet a majority of eye problems are treatable, so it’s important that people with Parkinson’s be screened and treated if possible.”
Colour Vision Contrast Sensitivity And Low Light Conditions
A lack of dopamine-producing cells in the retina can cause problems with colour vision and contrast sensitivity. This means that it may be hard to distinguish between shades of the same colour, particularly blues and blue/greens. Some people also have difficulty defining images on a background of similar shades or colours and reading fine print, particularly in low light levels.
Levodopa and other Parkinson’s medications may help with these problems. Your doctor will be able to advise you on this.
Vision: More Than Meets The Eye Tricks To Aid Pd Patients
Retired neurologist and young onset Parkinson’s patient, Dr. Maria De León reminds us that vision is integral to our quality of life and safety, especially with respect to driving. She lists 11 common eye problems with PD, and a few uncommon ones. They may be helped by adjusting medications, with special lenses, or artificial tears. See your doctor to find out.
What Are The Primary Motor Symptoms Of Parkinsons Disease
There are four primary motor symptoms of Parkinson’s disease: tremor, rigidity, bradykinesia and postural instability . Observing two or more of these symptoms is the main way that physicians diagnose Parkinson’s.
It is important to know that not all of these symptoms must be present for a diagnosis of Parkinson’s disease to be considered. In fact, younger people may only notice one or two of these motor symptoms, especially in the early stages of the disease. Not everyone with Parkinson’s disease has a tremor, nor is a tremor proof of Parkinson’s. If you suspect Parkinson’s, see a neurologist or movement disorders specialist.
Walking or Gait Difficulties
Ocular Motor And Sensory Function In Parkinson Disease
The purpose of this paper is to evaluate the effect of dopaminergic medication and deep brain stimulation on ocular function in Parkinson Disease and to measure vision-elated quality of life in subjects with PD. The conclusion is that convergence ability is significantly poorer in PD subjects in both “on” and “off” states compared with controls, but significantly improves with systemic dopaminergic treatment. Ocular motor function in PD subjects fluctuates in response to treatment, which complicates ophthalmic management. PD subjects have a significant reduction in vision-related quality of life, especially near activities, that it not associated with visual acuity.
Potential Effects Of Parkinsons Disease On Eyesight
Growing older often means a greater risk of experiencing certain vision problems, such as cataracts and age-related retina damage . Typically, these changes have nothing to do with Parkinson’s disease and can affect any older adult. However, there are some vision issues specifically related to this condition. Five of the more common ones are discussed below.
Structural Eye Changes & Color Perception Issues
Parkinson’s disease sometimes contributes to structural changes within the eye. It appears these changes are mostly limited to the retina, a thin layer of tissue in the back of the eye that converts light coming into the eye into nerve signals the brain uses to process visual information.If dopamine receptors in the retina are affected, one of the changes that could occur is a decrease in the ability to distinguish between different shades of color. Eye changes involving color perception sometimes contribute to vision-related disturbances that might include visual hallucinations.
Treatment Of Eye Problems In Parkinsons Disease
- Blurred vision – modification of anticholinergic medicine dose and adjustments in power if wearing glasses.
- Double vision – improves with anti-Parkinson medicines and by resting the eye.
- Dry eyes – using artificial tear drops and avoiding dry, hot and smoky places.
- Difficulty in moving the eyes – usually improves with anti-Parkinson drugs.
- Sensitivity to contrast – improves with treatment by levodopa.
- Color vision – problem may improve with anti-Parkinson medicines.
- Hallucinations – reducing the dose of anti-Parkinson drugs and use of neuroleptics such as clozapine and quetapine.
Is Vision Specifically Affected In Pd Dementia
Many of the oculo-visual features present in early and middle stage PD will become more severe if the patient develops PD dementia. However, some features appear to be particularly exacerbated in PD dementia including deficits in colour vision and changes in pupillary function . In addition, there are visual features which may be particularly characteristic of PD dementia. First, prominent visual hallucinations are significantly more frequent in PD dementia than PD . Second, severe eye movement problems are more likely to be present in PD dementia and to become more extensive with declining cognitive function . Third, defects in visuospatial orientation are likely to be greater in PD dementia especially when associated with greater cortical atrophy . Many additional visual features, already detected in PD, are likely to be present in a more severe form in PD dementia.
Ophthalmologic Features Of Parkinsons Disease
This paper is a systematic evaluation of the ocular complaints and ocular finding of 30 PD patients with early untreated PD, and 31 control subjects without neurologic or known ocular diseases. The ocular abnormalities found more commonly encountered by PD patients frequently respond to treatment. Abstract and access to the full article.
Molecular And Neurotransmitter Deficits In Pd
Although dysfunction of the dopamine neurotransmitter system has long been associated with the pathophysiology of PD accumulating evidence suggests that PD is a multisystem degeneration . Dopamine is an important neurotransmitter in the retina being present in amacrine cells along the inner border of the inner nuclear layer , and accumulated by interplexiform cells . Two types of amacrine cells appear to be involved: type 1 cells which send ascending processes to synapse with ?-aminobutyric acid interplexiform cells in stratum 1 of the INL and type 2 cells which have dendrites stratifying above those of the type 1 cells of the inner plexiform layer . Dopamine may be involved in the organisation of the ganglion cell and bipolar cell receptive fields and may modulate the physical activity of the photoreceptors . In addition, dopamine is involved in the coupling of the horizontal and amacrine lateral system . Thinning of the retinal nerve fibre layer has been recorded in PD . In particular, significant thinning of INL in parafoveal regions has been observed, especially in those patients exhibiting visual hallucinations but without overt signs of dementia .
Early Parkinson’s May Prompt Vision Problems
Changes in sight could signal disease a decade before motor symptoms surface, study suggests
The neurodegenerative condition is caused by the loss of neurons in several brain structures, resulting in tremors, rigidity or stiffness, along with impaired balance and coordination, the Italian researchers explained.
But, “although Parkinson’s disease is primarily considered a motor disorder, several studies have shown non-motor symptoms are common across all stages of the disease,” said lead researcher Dr. Alessandro Arrigo. He is a resident in ophthalmology at the University Vita-Salute San Raffaele of Milan.
“However, these symptoms are often undiagnosed because patients are unaware of the link to the disease and, as a result, they may be undertreated,” Arrigo added.
Non-motor symptoms in Parkinson’s disease patients include visual changes, such as an inability to perceive colors, a change in visual acuity, and reduced blinking, which can lead todry eye, the study authors noted.
These symptoms “may precede the appearance of motor signs by more than a decade,” Arrigo said.
This study included 20 newly diagnosed Parkinson’s patients who had not yet received treatment, and a “control” group of 20 people without the disease. Brain scans revealed that the Parkinson’s patients had significant abnormalities within the visual system brain structures.
Vision Problems Common In Parkinsons Disease We were unable to process your request. Please try again later. If you continue to have this issue please contact email@example.com.
People with Parkinson’s disease have a higher prevalence of ophthalmologic symptoms than those without the disease, according to research published in Neurology, the medical journal of the American Academy of Neurology.
“It is especially important for people with Parkinson’s to have the best vision possible because it can help compensate for movement problems caused by the disease, and help reduce the risk of falls,”Carlijn D.J.M. Borm, MD, of the Radboud University Medical Centre in Nijmegen, The Netherlands, said in a press release. “Our study found not only that people with Parkinson’s disease had eye problems that go beyond the aging process, we also found those problems may interfere with their daily lives.”
Borm and colleagues conducted an observational, cross-sectional study across multiple centers in the Netherlands and Austria as part of a larger study on visual impairments in patients with Parkinson’s disease.
The researchers evaluated the prevalence and clinical effects of ophthalmologic symptoms in adults using participant responses to the Visual Impairment in Parkinson’s Disease Screening Questionnaire. The questionnaire included questions on demographic information and visual hallucinations, and assessed the four domains of ophthalmologic disorders — ocular surface, intraocular, oculomotor and optic nerve.
Coping With Vision Problems From Parkinson’s
There is currently no cure for the disease itself, but there are options to treat the symptoms of PD. A combination of medications, physical and/or occupational therapy, support groups, and of course, top-quality vision care can give a PD patient relief for some of their symptoms and tools to help cope with the condition.
Research and clinical trials are continuing as doctors and others in the medical community work towards the goal of finding a cure for PD.
No two patients are alike, and each can experience PD differently from the other, so finding what works for you or your loved one is key. During this Parkinson’s Awareness Month, share your #KeyToPD and give your loved ones hope for a healthy and high quality of life.
Results Of A Visual Impairment Questionnaire
How Does Parkinsons Disease Affect The Body
Recognising the signs
A combination of signs can help a doctor make an early diagnosis. If Parkinson’s disease is diagnosed early, the chances of being able to treat and manage the condition are greater. Individual signs may not be an indication of Parkinson’s disease. Some signs such as loss of smell could be caused by an infectious illness, or joint stiffness by conditions like arthritis.
Parkinson’s is most commonly diagnosed with a very physical examination and assessment of a person’s medical history. There are very specific markers for diagnosis which doctors use to assess for possible Parkinson’s disease. These markers have a lot to do with a combination of very specific signs and symptoms and if recognised early enough, can be better managed.
1. Primary motor symptoms
2. Secondary motor symptoms
Other motor symptoms include:
Some individuals may also experience the following:
- Hunched over / stooped posture – When standing, the body may begin to slouch or lean inwards, causing a hunched over appearance.
- Impaired gross motor coordination
- Impaired fine motor dexterity and motor coordination
- Difficulties with swallowing or chewing
- Production of excess saliva and drooling
- Sexual dysfunction
3. Non-motor symptoms
Symptoms that do not involve physical movement or coordination, and often precede motor problems, can include:
Symptoms are initially mild, even if they develop suddenly, and typically affect one side of the body at first.
Progressive Supranuclear Palsy And Cortico
PSP and CBD are both four-repeat tau diseases exhibiting considerable similarities and overlap . Distinguishing PD from PSP can be especially difficult early in the disease. Atypical features of PSP include slowing of upward saccades, moderate slowing of downward saccades, the presence of a full range of voluntary vertical eye movements, a curved trajectory of oblique saccades, and absence of square-wave jerks . Hence, particularly useful in separating PSP from PD is the presence in the former of vertical supranuclear gaze palsy, fixation instability, lid retraction, blepharospasm, and apraxia of eyelid opening and closing . Downgaze palsy is probably the most useful diagnostic clinical symptom of PSP . Deficits in colour vision appear to be more important in PD and directly related to the dopamine system. However, in untreated early PD, no consistent deficits in colour vision were demonstrated making this alone an unreliable indicator of PD .
Medical Recognition Of Breathing Disorders
The existence of these breathing disorders have been known about, but largely ignored, in medical circles, for decades. Indeed, L.C. Lum, a cardiologist at Papworth & Addenbrookes Hospitals, Cambridge, UK, wrote an article on this entitled “Hyperventilation: the Tip of the Iceberg” in 1975. Here are some relevant excerpts:
“…this syndrome… shows up in medical clinics under many other guises. This is merely the tip of the iceberg; the body of the iceberg, the ninety nine per cent who do not present , presents a collection of bizarre and often apparently unrelated symptoms, which may affect any part of the body, and any organ or any system. The many organs involved are often reflected in the number of specialists to whom the patient gets referred, and my colleagues have variously dubbed this the ‘multiple doctor’ or the ‘fat folder syndrome’. Indeed the thickness of the case file is often an important diagnostic clue.”
Lum lists many symptoms, many of which are also common in PD: palpitations, disturbance of consciousness/vision, shortness of breath. “asthma” chest pain, dysphagia, muscle pains, tremors, tension, anxiety, fatigability, weakness, exhaustion, sleep disturbance nightmare, constipation, diarrhea, twitching eyelids, headache, giddiness, difficulty in breathing, weak limbs, painful limbs, vague pain, weakness, irritability, insomnia.
Involuntary Eye Closure & Eyelid Drooping
It’s not uncommon for seniors with Parkinson’s disease to experience involuntary eye closure . Eyelids may also droop due to muscle weakness or nerve damage caused by the disease. Both of these issues can narrow the field of vision and contribute to difficulty with navigation and coordination. Vision problems of this nature also increase the risk of falling for seniors with PD. Under certain circumstances, Botox injections may be recommended to address issues with eyelid drooping.
If your loved one is living with vision problems and needs assistance with daily tasks, help is available. Seniors can face a variety of challenges as they age, many of which can be mitigated with the help of professional in-home caregivers who provide high-quality elderly home care.Trust Home Care Assistance to help your elderly loved one age in place safely and comfortably.
Ask The Md: Vision And Parkinsons Disease
This webpage explains the visual problems that are due to Parkinson’s disease, the medications used to treat it, or to unrelated conditions of the eye or eyelid. If you have visual problems, don’t assume it is due to either aging or Parkinson’s. Address it with your doctor to maintain your ability to read, drive, and walk steadily to reduce your risk of falling.
My Parkinson’s Story: Visual Disturbances
This 6-minute video alternates between an interview with a man and and doctors. The man shares his vision changes due to Parkinson’s disease. The doctors explain that the muscles of the eyes develop a tremor in those with Parkinson’s disease, causing blurry vision. Parkinson’s medication reduces eye tremors by 75-90%, but eye exercises and reading are also beneficial.
Medication Side Effects & Vision Problems
Drugs or supplements taken to control the motor symptoms associated with Parkinson’s disease sometimes affect the eyes and contribute to vision-related problems. For this reason, it’s important for seniors to discuss all medications they’re taking for PD, including prescriptions and over-the-counter drugs, when they have their eyes examined. In some cases, making adjustments to these medications can enhance vision.
If your loved one is living with vision loss and needs assistance with daily tasks, help is available. Seniors can face a variety of challenges as they age, many of which can be mitigated with the help of professional in-home caregivers who provide high-quality Home Care Philadelphiafamilies trust Home Care Assistance to help their elderly loved ones age in place safely and comfortably.
Saccadic And Smooth Pursuit Eye Movements
Electro-oculography recordings have also been made before and after apomorphine treatment in early stage patients suggesting that smooth pursuit movements could be affected during the prodromal phase . In addition, patients with PD often have difficulty in sustaining repetitive actions and hence, smooth pursuit movements exhibit a reduction in response magnitude and a progressive decline of response with stimulus repetition.
Is Vision Affected In The Prodromal Stage
A number of oculo-visual features observed in early PD could be present in the prodromal phase of PD . First, autonomic system dysfunction is well documented in early PD and could affect pupil reactivity, and is a feature requiring further investigation. Second, electro-oculographic recordings have been made before and after apomorphine treatment confirming that smooth pursuit movements can be affected during the initial stages . Third, deficits in colour vision may occur early in the disease . Fourth, deficits in visuo-motor adaptation may occur during the early stages . Fifth, in PD cases in which idiopathic rapid eye movement sleep behaviour disorder is accompanied by abnormal stereopsis, postural instability may be an additional feature . The presence of any of these features in undiagnosed individuals may raise a concern of possible PD. Since early diagnosis may enable intervention and possible neuroprotection , further visual studies of the early stage PD are urgently needed.
Challenges With Controlling Eye Movements
Three types of eye movements could change with Parkinson’s: pursuit, saccadic, and vergence. Pursuit eye movements allow your loved one to follow an object as it moves, whereas saccadic motion directs the eyes to one specific thing. Vergence eye movements allow your loved one to roll his or her eyes in different directions. The inability to control eye movements could lead to visual difficulties and decrease independence.
If your loved one is experiencing issues with vision, he or she may get a great deal of benefit from having a professional caregiver help with everyday tasks. Families looking for top-rated elderly home care providerscan reach out to Home Care Assistance. From respite care to specialized Alzheimer’s, dementia, stroke, and Parkinson’s care, there are many ways we can make life easier for seniors and their loved ones.
How Does Parkinson’s Cause Vision Issues
Parkinson’s is characterized by a loss of dopamine producing cells in the substantia nigra portion of the brain. The reduction of dopamine can affect the visual cortex. So Parkinson’s can impair mobility of the eyes just like the limbs. There are several kinds of visual disturbances that may be experienced by people with Parkinson’s. Many who experience changes in vision or eye mechanics seek out a consultation from a neuro-opthalmologist, someone who specializes in visual problems associated with neurological disease.2
How Parkinsons Disease Can Affect Vision
The main characteristic of Parkinson’s disease is difficulty with movement that becomes increasingly noticeable as the condition progresses. However, there are many non-motor complications associated with this disease as well, one of which is vision impairment. Eye changes associated with age, such as the development of cataracts, can also affect seniors with PD, but we’re going to focus on vision issues specifically linked to Parkinson’s disease.
Exercises For Restoring Health Breathing
There are various suggested types of exercise which can help gradually shift the equilibrium point of CO2 intolerance back to healthy states. However, all of these emphasize nose breathing over mouth breathing , and diaphragmatic breathing over chest breathing. This represents an immediate roadblock for people with PD, for whom mouth breathing is likely to have become so ingrained that it feels like the nose is permanently stuffed up, and who have diaphragms which are so frozen that it cannot voluntarily be flexed. However, it is possible to open the nose in the majority cases through some simple exercises. Robert Litman in the above video demonstrates this, and below is another video of Patrick McKeown on the topic. See also my article on how I restored nose breathing with the help of a red light anti-allergy device. It is also possible to restore access to diaphragmatic breathing, as I covered in another article, which explains how I used Block Therapy to achieve this.
Once nasal and diaphragmatic breathing is made possible there are a few different types of breathing exercises one try for restoring CO2 tolerance to more normal levels. It is important to note that these exercises are not necessarily targeted at immediate regulation of the Nervous System, unlike breathing methods designed for in-the-moment relaxation or mobilization, but are aimed at long term retraining of breathing patterns in order to restore healthy oxygenation levels to the brain and muscles.
Blurred Vision And Difficulty Focussing
Some Parkinson’s medications, in particular anticholinergics, can cause blurred vision and difficulty focussing. You may find your vision is blurred if you start taking anticholinergics and that this goes away when your body gets used to the new drug. This can also happen if you have been taking anticholinergics for some time but your dose is altered. If necessary your doctor may adjust your medication regime.
Talk with your doctor if blurred vision does not improve – or worsens – over time, so that your medication can be adjusted if necessary. If you wear reading glasses, a slight adjustment may also help. Your optician or optometrist should be able to help with this.
How Parkinsons Disease Affects The Body Ricky Chen, M.D.
Life with Parkinson’s is challenging, to say the least. This progressive disease starts slowly, and because there’s currently no cure, it gradually worsens how you think and feel.
Giving up may seem like the only solution, but it certainly isn’t. Thanks to advanced treatments, many people are able to continue living healthy, productive lives with Parkinson’s.
Take a glance at this infographic to get a visual picture of how Parkinson’s can affect everything from your memory to your movement.
Lower Dopamine Levels & Vision Changes
Seniors with Parkinson’s are affected by the loss of a chemical called dopamine, a neurotransmitter that helps with the transfer of signals between nerve cells in the brain. Lower levels of dopamine may also affect a region of the brain called the visual cortex, which processes visual information. These changes could affect eye mobility, which sometimes results in visual impairment. According to the American Parkinson Disease Association , there are three types of eye movement that may be affected by PD: • Pursuit eye movements, which allow the eyes to follow objects• Saccadic eye movements, which allow the eyes to jump from one target to another • Vergence eye movements, which help eyes adjust and maintain clear focus when an object is coming closer
Seniors with severe vision impairment may need assistance to be able to continue living at home. For many seniors in Philadelphia, PA, live-in care is an essential component of aging in place safely and comfortably. However, it’s important for them to have caregivers they can trust and rely on. At Home Care Assistance, we extensively screen all of our live-in and 24-hour caregivers and only hire those who have experience in the senior home care industry. Our strict requirements ensure seniors can remain in the comfort of home with a reduced risk of injury or serious illness.
How Parkinsons Disease Affects The Eye
Parkinson’s disease is a progressive degenerative condition of the neurological system. The majority of Parkinson’s effects are on movement, often starting off very slowly and subtly. One of the earliest symptoms is a slight tremor in one or both hands. Other early symptoms include a lack of facial expression and decreased blinking of the eyes, so it looks like the person is always staring.
The next stage usually results in difficulty with initiating movement, especially walking. It frequently looks like it takes a tremendous concentrated effort to initiate walking and the steps often start off very small with a shuffling of the feet. At the same time, the disease stiffens the muscles of the arms so that when the person is walking there is a noticeable decrease in the swinging of the arms. Speech becomes much softer and writing becomes more of an effort, with handwriting getting smaller and smaller as the disease progresses.
Parkinson’s can also affect your visual performance, mainly in two parts of your eyes: the tear film and the ocular muscles.
If you don’t blink enough, the tear film begins to dry out in spots and having dry spots next to moist spots results in an irregular film and therefore blurred vision. That is how the decreased blinking frequency in people with Parkinson’s disease results in a complaint of intermittent blurred vision.
The majority of these problems do improve if the Parkinson’s is treated with medication or even brain stimulation.