• Reference Number: HEY1681/2026
• Departments: Ophthalmology Department
• Last Updated: 30 June 2026

Introduction

This leaflet has been produced to give you general information about your condition. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and your doctor but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team caring for you.

What is Herpes Simplex Keratitis?

Herpes Simplex Keratitis is a viral infection of the cornea (the clear surface, or ‘window’ of the eye). It’s caused by the same virus that causes cold sores (HSV-1). HSV Keratitis generally affects 1 eye but can occasionally affect both.

Symptoms may include:

• A red eye
• Eye pain or foreign body sensation
• Sensitivity to light
• Blurred vision

How have I got it?

HSV-1 is a common virus which is passed on by direct skin-to-skin contact.

The infection is usually picked up in childhood, but only 1 in 3 people will develop symptoms. After the initial infection, the virus remains in the nerves of the face and can reactivate at any time. It can cause a cold sore, or an ulcer in the eye.

The virus can spread directly to the eye from a cold sore, so avoid touching your eyes if you have a cold sore present.

What is the treatment?

• Antiviral eye gel – a course of ganciclovir is the most common treatment.
• Antiviral tablets – a 7-day course of antiviral tablets (aciclovir/ valaciclovir).
• Steroid eye drops – sometimes used to reduce inflammation & minimise scarring.

Contact lenses should not be worn until all symptoms have resolved.

Can there be any complications/ long term effects?

The HSV-1 virus is a recurrent problem. Like cold sores, the virus can flare up at any time.

If you keep getting recurrent flare ups of the virus, the Ophthalmology Doctor may recommend a course of antiviral tablets to help prevent further flare ups.

Severe or recurrent episodes can lead to scarring on the cornea, which can cause blurred vision.

When to seek advice

If you develop redness, pain, light sensitivity or blurry vision, you should contact the Eye Clinic Triage Nurses ASAP.

Severe or recurrent episodes can lead to scarring on the cornea. When symptoms reoccur an examination in the eye clinic is required to start treatments ASAP.

A recurrent ocular conditions (ROC) card will be given to you; this gives you access to be re booked back into the eye clinic should your symptoms return

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Ophthalmology Triage Nurses on Tel: 01482 816658

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

• you must be able to give your consent
• you must be given enough information to enable you to make a decision
• you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.