Frequently asked questions about eye health

Floaters are commonly seen as small dark spots or lines that appear to float around in front of your eyes.  If you are short-sighted you are more likely to see floaters.  It is also more likely that you’ll see floaters as you get older.  If the floaters have been there for some time, your brain will learn to ignore them so that you don’t notice them. In the majority of cases, floaters are harmless. Some people are born with floaters and in other cases, they occur as you get older when the gel inside the eye (known as the vitreous humour) naturally shrinks.  

Occasionally, floaters can indicate a problem inside the eye. It is possible for the gel inside the eye to shrink enough that it begins to pull at the retina (the light-sensitive layer of cells at the back of the eye). This is referred to as a Posterior Vitreous Detachment. In some cases, the retina can begin to detach. A retinal detachment is sight-threatening therefore you must contact your Optometrist straight away if you suddenly notice floaters in your vision or you notice a sudden increase in the number of floaters. Other symptoms that require immediate attention are flashes of light in the periphery of your vision or a greying of vision. 

If you are unable to seek immediate assistance from your Optometrist, you should seek advice from your local eye casualty department.

Glaucoma is a term used to describe a group of eye diseases in which the optic nerve (the structure that connects the eye to the brain) becomes damaged. Damage to the optic nerve can be caused by an increase in pressure inside the eye that falls out with what is considered to be normal eye pressure. Damage could also happen if the optic nerve is more susceptible to damage from the pressure that naturally occurs inside the eye.  

Glaucoma can be either a chronic condition meaning that it develops slowly or an acute condition meaning that it develops quickly.

In the early stages, those with chronic glaucoma do not have any symptoms and the condition is often first detected through a routine eye examination. It is therefore essential that you attend routine regular eye examinations at least once every two years (or more often if directed to do so by your Optometrist) to maintain good eye health.

Acute glaucoma can cause eye pain, nausea and/or blurred vision that either comes and goes or is constant. If you experience these symptoms you must contact your Optometrist straight away.

A stye (also known as an external hordeolum) is a term used to describe a bacterial infection of the glands associated with the eyelashes. The condition causes red and sometimes painful swelling of the eyelid.

A stye usually resolves with warm compresses applied a few times per day. Sometimes, it may be useful to use antibiotic eye drops or eye ointment. Contact lens wearers should refrain from using their contact lenses when a stye is present.

The conjunctiva is the thin membrane that lines the inside of the eyelids and the white part of the eye (known as the sclera). Conjunctivitis describes inflammation of the conjunctiva and can affect either one or both eyes. There are several types of conjunctivitis that are defined according to their cause. Depending on the type and severity of conjunctivitis, symptoms can include itching, burning or stinging of the eyes, redness and/or a yellow sticky discharge in the eye.

Conjunctivitis can be caused by a viral or bacterial infection or can be a reaction caused by an allergy.

Your Optometrist will be able to advise on the best treatment for your conjunctivitis. Treatment is planned, depending on the cause of conjunctivitis. For example, if the conjunctivitis is caused by an allergic reaction, anti-allergy medications may be the best treatment whereas if the conjunctivitis is caused by a bacterial infection, antibiotics may be prescribed. In some cases, treatment with medication is not necessary.

How long conjunctivitis lasts depends on its cause and can range from resolving within a few hours to resolving within a couple of weeks.

When caused by a virus or bacteria, conjunctivitis can be highly contagious. The condition can be spread through hand-to-eye contact and as such care needs to be taken to prevent others from becoming infected. For example, sharing towels should be avoided.

Blepharitis is a chronic (long-term) inflammation of the eyelids which can cause your eyelids to look red and can make your eyes feel itchy or generally irritated. Some crusting can also be seen on the eyelashes. The symptoms are commonly worse in the morning and can cause the eyelids to be stuck together on waking.  

Blepharitis can either be caused by bacteria (known as anterior blepharitis) or may be caused by a blockage of the glands that are found along the eyelid (known as posterior blepharitis or meibomian gland dysfunction).  Some skin conditions that cause blepharitis to develop.

Because blepharitis is a chronic (long-term condition) there is, unfortunately, no treatment that will ensure the condition never returns.   Blepharitis treatments will improve the discomfort caused by the condition and will help maintain good eye health. To alleviate the symptoms of blepharitis, you can apply warm compresses. These work by warming the material that is causing the glands in the eyelids to become blocked.   They can also warm and loosen crusting on the eyelashes. After using a warm compress, you can carefully clean your eyelids. Your Optometrist will be able to offer you advice on the different methods that can be used to safely clean your eyelids.

Blepharitis is not contagious.

Dark circles can have several causes including lack of sleep, dehydration, allergies, hayfever and hyperpigmentation.

If you want to find out more about the causes of dark circles, click here.

Dry eye is a common condition that can occur through a variety of different causes. Dry eye may occur because the tears in your eyes evaporate too quickly or your eyes do not produce enough tears. Factors such as time spent using a computer or tablet, the use of contact lenses and certain medications can cause dry eye. Dry eye can also be caused by certain general health conditions. Usually, this condition affects both eyes.

Symptoms of dry eye include irritated eyes or a burning sensation in the eyes.  If it is severe, dry eye can cause your vision to become temporarily blurred.

The term macular degeneration is used to describe a number of conditions which affect the normal functioning of the macula. The macula is the area of the back of your eye that is responsible for your central vision and seeing fine detail.

When macular degeneration develops, it can make it harder to see fine detail and affects your ability to for example, read, watch television or recognise peoples faces. Your peripheral vision is not affected.

The uvea is the term clinicians use to describe the area of the eye that lies underneath the white part of the eye (known as the sclera).  The uvea is comprised of eye structures known as the iris, the ciliary body and the choroid. When the uvea becomes inflamed, we call this uveitis. 

Uveitis can be caused by an eye infection or by an eye injury. Symptoms can include eye redness, sensitivity to light, blurred vision and/or a dull ache in the eye. Usually, the condition affects one eye rather than both eyes. If you experience any of the symptoms of uveitis you must contact your Optometrist without delay.

Nystagmus is a condition that causes the involuntary movement of the eyes. Most people who have nystagmus also have reduced vision and reduced depth perception. Usually, people with nystagmus are born with the condition. In some cases, nystagmus can develop later in life.

If the light-sensitive layer of cells at the back of the eye becomes loose and detaches from the rest of the eye we call this a retinal detachment.

A retinal detachment can cause permanent loss of vision and as such symptoms associated with this condition must be investigated as a matter of urgency. If you suddenly notice floaters (dots or lines in vision) an increase in the number of these or if you notice flashes of light in vision, a dark shadow or curtain moving across your vision or if you notice your vision suddenly becomes blurred you must contact your Optometrist straight away. If you are unable to contact your Optometrist, you must seek advice from your local eye casualty department.

The term ptosis is used to describe an eyelid which droops over the eye, sometimes affecting vision. Some people are born with ptosis however it more commonly occurs later in life. You can discuss the various options for treating ptosis with your Optometrist.

The cornea is the structure at the front of the eye that extends over the coloured part of the eye known as the iris. The cornea can be thought of as the outer window of the eye. The term Keratoconus describes the progressive weakening and thinning of your cornea which causes it to bulge outwards in an irregular cone shape.  

Keratoconus usually develops in your teens or in your 20s and tends to get worse over time.  Traditionally specialist contact lenses that can alter the shape of the cornea are used to improve vision for those with keratoconus however this does not help to slow down the progression of the condition.