• Feel Good Contacts
  • 01 514 3614
  • Need Optical Advice?
  • OFFERS
    • 10% off First Order
    • 5% off on Auto Replenish
    • Glasses up to 70% off
    • Sunglasses up to 60% off
    • Refer a Friend
    • Earn Reward Points
    • Student Discount
  • Contact Lenses
    Top Brands
    • Acuvue
    • Air Optix
    • Alcon / Ciba Vision
    • Bausch & Lomb
    • Biofinity
    • Clariti
    • Comfi
    • Cooper Vision
    • Focus Dailies
    • Freshlook
    • All Brands
    Type
    • Daily Contact Lenses
    • Monthly Contact Lenses
    • Two Weekly Contact Lenses
    • Toric/Astigmatism Lenses
    • Multifocal Contact Lenses
    • Coloured Contact Lenses
    • Cheap Contact Lenses
    • Next Day Contact Lenses
    • Extended Contact Lenses
    • Silicone Hydrogel Lenses
    • No Prescription Lenses
    Top Sellers
    • comfi Daily Disposable
    • 1 Day Acuvue Moist
    • Dailies AquaComfort Plus
    • Acuvue Oasys 1-Day with HydraLuxe
    • Acuvue Oasys
    • 1 Day Acuvue Moist For Astigmatism
    • Air Optix Aqua
    • FreshLook Colorblends
    • Biofinity
    • 1 Day Acuvue Moist Multifocal
    Buyer's Guide
    • Save with comfi
    • Which comfi is for you?
    • How to put in contact lenses
    • How to clean your contact lenses
    • Guide to Astigmatism
    • Glasses prescription vs contact lens prescription
    • Best contact lenses for dry eyes
    View All Contact Lenses
    feel good contacts menu feel good contacts menu
  • Solutions
    Top Brands
    • Boston
    • Biotrue
    • Comfi
    • EasySept
    • Ote Optics
    • Opti Free
    • OxySept
    • ReNu
    • Total Care
    • All Brands
    Type
    • Multi Purpose Solutions
    • Saline Solutions
    • Peroxide Solutions
    • Travel Pack Solutions
    • Rigid & Gas Permeable
    • Multi Pack Solutions
    Top Sellers
    • comfi All-in-One Solution
    • Biotrue Multi-Purpose Solution Twin Pack
    • Delta Plus Disinfecting Soaking and Wetting Solution
    • ReNu Multi-Purpose Solution Triple Pack
    • Opti-Free Express Twin Pack
    • Opti-Free RepleniSH Twin Pack
    • Refine One Step Solution - 250ml Triple Pack
    Buyer's Guide
    • How to clean and store soft lenses
    • Which contact lens solution do I need?
    • How to clean a contact lens case
    View All Solutions
    feel good contacts menu feel good contacts menu
  • Eye Care
    Top Brands
    • Altacor
    • Artelac
    • Biotrue
    • Comfi
    • Blink
    • Hycosan
    • Optase
    • Systane
    • The Body Doctor
    • Thea
    Eye Care
    • Eye Drops
    • Eye Accessories
    • Dry Eye Treatments
    • Supplements & Hygiene
    • Face Masks
    • Covid Essentials
    • Travel Essentials
    Top Sellers
    • comfi Soothe Drops
    • Blink-N-Clean Eye Drops
    • Blink Intensive Tears Vials
    • Clinitas Soothe Multi
    • Feel Good Contact Lens Case
    • Feel Good Cleaning Kit
    • Hycosan Extra Dry Eye Drops
    • The Eye Doctor Lid Wipes
    • Thera-Pearl Eye Mask
    • The AB Mask Anti-Fog Cloth
    Buyer's Guide
    • How to use eye drops
    • How to stop itchy eyes from hay fever - for good
    • Computer Eye Strain:
      Symptoms and Solutions
    View All Eye Care
    feel good contacts menu feel good contacts menu
  • Glasses
    Gender
    • Women
      Glasses for women
    • Men
      Glasses for men
    Brands
    • Calvin Klein
    • Chloe
    • DKNY
    • Dolce & Gabbana
    • Emporio Armani
    • Feel Good Collection
    • Gucci
    • Hugo Boss
    • Lacoste
    • Le Specs
    • Marc Jacobs
    • MaxMara
    • Michael Kors
    • Oakley
    • O'Neill
    • Polaroid
    • Polo Ralph Lauren
    • Prada
    • Radley
    • Ralph by Ralph Lauren
    • Ray-Ban
    • Superdry
    • Tommy Hilfiger
    • Versace
    • Vogue
    Frame Shapes
    • Aviator Aviator
    • Oval Oval
    • Rectangle Rectangle
    • Round Round
    • Square Square
    • Wayfarer Wayfarer
    • Clubmaster Clubmaster
    • Cat Eye Cat Eye
    • Butterfly Butterfly
    • Hexagonal Hexagonal
    Special Offers
    • Clearance
    • New Arrivals
    • Best Sellers
    Price Range
    • €7 - €30
    • €30 - €70
    • €70 - €100
    • €100+
    Advice & Top Tips
    • Glasses prescription
    • Glasses frame size guide
    • Glasses lens options
    • Glasses lens coatings
    • How to tighten my glasses
    View All Brands View Blue Light Glasses
    feel good contacts menu feel good contacts menu
  • Sunglasses
    Gender
    • Women
      Sunlasses for women
    • Men
      Sunglasses for men
    Brands
    • Calvin Klein
    • Carrera
    • Chloe
    • Dolce & Gabbana
    • Dunlop
    • Feel Good Collection
    • Gucci
    • Hugo Boss
    • Jimmy Choo
    • Kendall + Kylie
    • Lacoste
    • Le Specs
    • Linda Farrow
    • Oakley
    • O'Neill
    • Persol
    • Polaroid
    • Police
    • Prada
    • Radley
    • Ray-Ban
    • Saint Laurent
    • Superdry
    • Tommy Hilfiger
    • Versace
    • Victoria Beckham
    • Vogue
    Frame Shapes
    • Aviator Aviator
    • Oval Oval
    • Rectangle Rectangle
    • Round Round
    • Square Square
    • Wayfarer Wayfarer
    • Wrap Wrap
    • Clubmaster Clubmaster
    • Cat Eye Cat Eye
    • Butterfly Butterfly
    • Hexagonal Hexagonal
    • Octagonal Octagonal
    • Heart Heart
    Advice & Top Tips
    • Sunglasses tints
    • Face shape guide
    • Types of sunglasses
    • UV protection guide
    Special Offers
    • Clearance
    • New Arrivals
    • Best Sellers
    Lens Coatings
    • Polarised
    • Mirrored
    • Gradient
    Price Range
    • €15 - €50
    • €50 - €80
    • €80 - €120
    • €120+
    View All Brands View Collections
    feel good contacts menu feel good contacts menu
  • Help
    Customer Information
    • Contact Us
    • Delivery Information
    • Returns & Exchange
    • FAQ
    Customer Advice
    • Eye Care Hub
    • Optical Advice
    • Free Eye Test
    • Advice on Covid-19
    Popular Content
    • No Prescription Needed
    • Contact Lens Prescription
    • Glasses Prescription
    • Guides to Brands
    Tools
    • Vision Simulator
    • Dry Eye Quiz
    feel good contacts menu feel good contacts menu
  • Blog
  • search feel good contacts blog
  • search feel good contacts
  • 0
  • Reorder
  • Login Login
      feel good contacts menu
    • My Account
    • Orders
    • Personal Details
    • Log out
    feel good contacts menu
    Existing Customer

    We've sent you an email
    to reset your password.

    Enter your email address

    I would like to receive friendly reminders when it’s time to re-order. I am aware I can easily unsubscribe from these at any time.
    NEW Customer
    Forgot Password Cancel
Price match guarantee
Order by 5:45pm for same day dispatch
Excellent
Reward points
Home
Eye Care Hub
Anisocoria and Horner’s Syndrome

Contact Lens Care

  • Which contact lens solution do I need?
  • How to clean a contact lens case?
  • How can I tell if my contact lens is inside out?

About Contact Lenses

  • How do toric contact lenses work?
  • What does the water content of a contact lens mean?

Eye Health

  • What are the best contact lenses for dry eyes?
  • How dehydration impacts your eyes?
  • Computer eye strain: Symptoms and solutions

Children's Eye Health

  • Why does my child get styes?
  • At what age can my child wear contacts?
  • How can I tell if my child has vision problems?

Lenses & Lifestyle

  • Which sunglasses will suit my face shape?
  • What are polarised sunglasses?
  • Guide to different types on sunglasses?

Prescriptions & Eye Tests

  • Difference between an Ophthalmologist, Optometrist & Optician
  • What does axis mean on my prescription
  • Can I buy my contact lenses online

Guides

  • A guide to Astigmastism
  • A guide to eye discharge
  • A guide to Presbyopia

Anisocoria and Horner's Syndrome

Medically reviewed by Alastair Lockwood on 08 March 2021

Anisocoria is a condition where one pupil is larger than the other. You can be born with anisocoria or develop it later in life.

Several factors can cause anisocoria, including Horner's syndrome. In this case, an underlying medical condition may be diagnosed by the doctor. This article looks at Horner's syndrome and its relationship to anisocoria.

What is Horner's syndrome?

Horner's syndrome, also known as Horner-Bernard syndrome or oculosympathetic palsy is a rare disorder resulting from nerve damage. The symptoms of Horner's syndrome include a drooping upper eyelid, unequal pupil sizes and a constricted pupil on the affected side. People with congenital Horner's syndrome often have a lighter coloured iris of the eye on the affected side compared to the iris of the eye on the unaffected side.

Horner's syndrome is the result of a disrupted nerve pathway from the brain to the face and the eye on one side of the body. The pathway is triggered as part of the “fright / fight /flight” reflex. The underlying causes for this vary and, in some cases, an underlying cause cannot be found.

Congenital Horner's syndrome is when the condition is passed down through families and is present from birth. Acquired Horner's syndrome appears after the newborn period. Both are the result of damage to the sympathetic nervous system.

Can Horner’s syndrome affect both eyes?

Horner's syndrome typically affects one side of the face, affecting only one eye. It does not usually cause problems with a person's vision.

How is Horner’s syndrome related to anisocoria?

The sympathetic nerves are responsible for dilating the pupil and raising the eyelid. Horner's syndrome is caused when these nerves are damaged.

Damaged sympathetic nerves cause the pupil in the eye on the affected side to become smaller compared to the eye on the unaffected side. The affected eye also has problems dilating. When the pupils in both eyes are different sizes at the same time, this is known as anisocoria.

Horner’s syndrome symptoms and causes

Signs and symptoms associated with Horner's syndrome usually only affect one side of the face.

What are the three classic signs of Horner's syndrome?

The three classic signs of Horner's syndrome are:

  • A constricted pupil (miosis)
  • Drooping of the upper eyelid (ptosis)
  • Reduced sweating or no sweating on the whole side of the face or a patch on the affected side of the face (anhidrosis)

Other symptoms of Horner's syndrome include:

  • A sunken appearance to the eye (enophthalmos)
  • A difference in pupil size (anisocoria)
  • Delayed pupil dilation or little pupil dilation in dim light
  • A slight elevation of the lower lid

Children with Horner’s syndrome might have additional signs and symptoms, including:

  • A lighter iris colour in the affected eye
  • Lack of flushing (on the affected side) as a result of heat, emotional reactions or physical exertion

Causes of Horner’s syndrome

Horner's syndrome is a result of nerve damage from injury, compression or disease. Causes include:

  • Neck or shoulder injury during birth
  • A stroke in the brainstem
  • Trauma to the neck, chest or upper spinal cord (or surgery involving them)
  • Migraines
  • Tumours
  • Lung cancer
  • Damage to the aorta
  • Injury

The cause of Horner’s syndrome is not always identifiable. These cases are known as idiopathic Horner syndrome.

Does Horner's syndrome cause pain?

Horner's syndrome can have associated sudden neck pain and headaches, depending on the cause.

What nerve is damaged in Horner's syndrome?

The nerves that are damaged in Horner's syndrome are part of the sympathetic nervous system. These in part run independently and in part are carried by other nerves, eg: occulomotor nerve. The sympathetic nervous system regulates the functions that enable you to respond to changes in your environment. It is sometimes referred to as your body's 'fight or flight' response.

The oculosympathetic pathway is responsible for sending messages from the brain to the eye. The signals in this pathway send messages to your body so that it can respond to stress.

Does Horner’s syndrome go away?

Horner's syndrome will often go away if the underlying cause is reversible. If the nerves have been physically interrupted, the effects are frequently permanent.

What can be done for Horner's syndrome?

The management of Horner's syndrome entails understanding the underlying cause and excluding the serious ones. Treatment then depends on this underlying cause and might include:

  • Surgery, chemotherapy or radiation (for cancer)
  • Antibiotics for infectious diseases
  • Anti-inflammatory drugs
  • Clot-dissolving agents (for certain strokes)
  • Minimally invasive treatments (for carotid artery dissection)

Diagnosis of Horner's syndrome

Diagnosing Horner's syndrome can be challenging as there are many other medical conditions which have the same symptoms, such as a dilated pupil or a drooping eyelid. Other conditions with these symptoms include optic neuritis and third nerve palsy.

Those with anisocoria should consider getting a diagnosis for Horner's syndrome. A dilation lag of the smaller pupil will help determine if one has Horner's syndrome. It also helps to distinguish the symptoms from physiologic anisocoria.

Sometimes the underlying cause of Horner's syndrome is harmless; however, other times, it can be life-threatening, for example, lung cancer, carotid artery dissection or neuroblastoma.

A detailed account of medical history and a physical exam are essential for the diagnosis of Horner's syndrome. A doctor will ask questions about the symptoms to try and decipher the underlying cause. They will also ask questions to see if Horner’s syndrome is the result of medication or injury from a medical procedure.

Patients with Horner's syndrome will also undergo an eye exam. During the exam, the doctor will look at their pupillary dilator muscle by seeing how their pupils respond to light and dark. The eye exam will also check eye movement.

Pharmacologic tests

Pharmacologic tests are sometimes used to help diagnose where the interruption of the nerve supply is in Horner's syndrome. This includes using apraclonidine eye drops or cocaine to see how your eye responds.

Quick links

A guide to Anisocoria
A guide to tetrachromacy
A guide to Exophthalmos (bulging eyes)
Please wait
Why Us
  • 10% Off Your First Order
  • Price Match Guarantee
  • 5% Off with Auto-Replenish
  • Feel Good Contacts App
  • Save with comfi
  • Which comfi is for you?
  • Trustpilot Reviews
  • Student Discount
  • Reward Points
  • Reasons to Feel Good
Top Products
  • 1 Day Acuvue Moist
  • Dailies AquaComfort Plus
  • comfi Daily Disposable
  • Acuvue Oasys 1-Day with HydraLuxe
  • Dailies Total 1
  • Acuvue Oasys
  • 1 Day Acuvue Moist For Astigmatism
  • Air Optix Aqua
  • FreshLook Colorblends
  • Biofinity
Order Information
  • Optician Own Brand Contact Lenses
  • No Prescription Needed
  • Delivery Information
  • Returns and Exchange
  • Secure Online Shopping
  • Contact Lens Specifications
  • Optical Advice
  • FAQs
  • About Us
Contact Us
  • 01 514 3614
  • +44 7810 004 929 (WhatsApp)
  • +44 7810 004 929 (WhatsApp)
  • cs@feelgoodcontacts.ie
Customer Service Hours

Mon - Fri: 8:00am - 9:00pm
Sat - Sun: 9:00am - 5:30pm
Bank Holidays: 9:00am - 5:30pm

Download the app
Countries
  • feel good contacts united kingdom
  • feel good contacts ireland
  • feel good contacts france
Secure Payments Secure Payments
Secure Payments
©2023 Feel Good Contacts Ltd. All Rights Reserved.
T&Cs Privacy Policy Cookie Disclaimer Affiliate Program
Top