Eye Related Questions
Symptoms and history are very important when trying to establish the cause of headaches so we will need to know:
- How long you have had them for?
- How often do they occur and at what time of day?
- Is there a recognised pattern?
- Whereabouts on the head does it ache?
- What makes it better/worse?
- Are there any associated symptoms such as nausea or visual disturbances?
If headaches appear to be associated with specific visual tasks such as computer work, reading or driving we can investigate how well the eyes work and focus for these tasks. Many problems can easily be resolved with appropriate spectacles.
If an ocular cause is unlikely to be causing headaches, our checks on the relevant aspects of your eye health and visual function will be noted, if necessary, in a referral to your GP.
Glaucoma is the second most common cause of blind registration in the UK. The condition involves damage to the optic nerve caused by raised pressure in the eye.
Open angle glaucoma
The eye contains fluid called aqueous, which is constantly being produced within and drained from the eye. The internal ocular pressure (IOP) of the eye is determined by the balance between the production and drainage of the aqueous. In glaucoma, too much aqueous is produced and not enough is drained; this leads to a pressure increase and the optic nerve becomes slowly damaged.
Optic nerve damage in glaucoma results in loss of peripheral vision and if untreated can progress until all vision is lost.
If you are at risk of glaucoma regular screening and early diagnosis is crucial.
Who is at risk?
Glaucoma can affect anyone but certain groups are more at risk than others. These include:
- People over 60 years of age
- People who have a parent or sibling with glaucoma
- People with myopia (short-sightedness)
Other indicators include:
- Suspicious optic nerve cupping
- Higher than average intra-ocular pressure
- Thin corneas
- Narrow anterior chamber angles.
If you are diagnosed with glaucoma the most common treatment is the use of prescribed eye drops which reduce aqueous production and increase drainage resulting in a lowering of the eye pressure.
Closed angle or acute glaucoma?
Aqueous leaves the eye through a drainage angle. Very narrow angles can restrict outflow, raising the pressure and if the angle closes completely the pressure can get very high very quickly resulting in an extremely painful eye. This is called acute glaucoma. It is an emergency and needs immediate treatment by a specialist. Luckily, acute glaucoma is extremely rare.
Age Related Macular Degeneration
Age related macular degeneration (ARMD) is the largest single cause of blindness in the UK. The macular is the very centre of the retina and macular damage results in loss of central vision causing great difficulty with tasks such as reading, recognising faces etc.
Risk factors for ARMD
Risk factors for ARMD include:
- Having a close family member with the condition
- A diet high in fat and cholesterol and low in antioxidant-containing fruit and vegetables
- Age – the older you are the higher the risk
- High levels of sun exposure
- Having blue eyes and fair skin.
How ARMD is treated
There is no effective treatment for dry ARMD but there is growing evidence that a diet rich in antioxidants (particularly macular pigments) may reduce the risk of progression.
Wet ARMD can be treated but needs to be caught early. The earliest sign of a blood vessel leaking at the macular will show itself as distortion in your central vision. Anyone noticing distortion needs to attend the practice that day so that we can confirm the diagnosis and take the appropriate action.
The macular contains a yellow pigment that acts like ‘sun screen’ protecting the macular from the damaging effects of short wavelength blue light and neutralising free radicals in the same way that sun screen protects the skin from burning and premature ageing. Low levels of macular pigment increase the risk of ARMD.
If you have a close relative with macular degeneration then you should consider eating more vegetables that are naturally rich in macular pigments as well as taking sensible precautions to reduce risk such as not smoking and wearing sunglasses in bright conditions.
Floaters & Flashes
The sudden onset floaters and flashing lights is one of the most common problems reported to Optometrists.
Floaters are often described as looking like ‘grey spots’, ‘tadpoles’ ‘broken rings or ‘cobwebs’ in the vision that move away as the eye moves towards them. They are regularly associated with flashes of light in the side vision.
These symptoms are common and are caused by a natural process in the eye that involves the vitreous jelly inside the eye peeling away from the retina. This ‘rearrangement’ of the jelly is called a posterior vitreous detachment (PVD) and is quite normal. The jelly takes about five weeks to peel away completely and during this process floaters and occasional flashes are normal.
However things do not always go smoothly. In a very small percentage of people, the vitreous becomes ‘snagged’ on a piece of retina as it peels away, so that as the eye moves the weight of the vitreous is pulling on one small piece of retina. This can result in a retinal tear.
Retinal tears are a real concern as if they are not treated quickly they can progress to a retinal detachment which is much more serious. Detachments are emergences and need to be seen by an eye specialist immediately so that the retina can be reattached and the sight can be saved.
What you should do if you notice floaters or flashes
Anyone with sudden onset floaters and flashes needs to be examined by an optometrist immediately to check for retinal holes or tears. Even if the eye is fine it should be checked again after about five weeks, when the jelly has peeled away completely, to make sure that no tears have formed during the process of peeling. During this time you can monitor your own eyes, looking out for symptoms that may suggest a tear or detachment.
These symptoms include:
- A sudden increase in floaters – often more than you can count
- The flashing lights increasing in intensity over time rather than decreasing
- Shadows in the vision or grey areas where vision is lost.
We would expect the symptoms to get better over time so any sudden increase in symptoms is a concern and needs to be investigated immediately.
What do we do if we find a retinal tear?
Tears in the retina need to be treated straight away to stop them progressing to a detachment. Luckily, tears are very easy to treat. A laser is used to make small burns in the retina all the way around the tear. The burn forms a scar and the scar ‘welds’ the retina down so that it cannot detach. This whole procedure is quick, simple and painless.
Remember, if you notice sudden onset floaters, flashes or both you need to be seen straight away. Only a minority of people will have retinal complications but for those who do, early treatment is essential.
Diabetes is a condition that can cause eye problems. Regular, high quality eye care should be a priority for any diabetic.
Ideally, we suggest that all diabetics are examined with drops in the eyes to dilate the pupils. This allows for a better view of the retina and helps the optometrist to find any retinal abnormalities such as leaky blood vessels. This can also be complimented with a high-resolution retinal photograph to help identify any subtle changes in the central retinal area.
Diabetic eye problems can be successfully treated with a laser, sealing leaky blood vessels and destroying retinal abnormalities such as new vessels.
You can help by making sure that you:
- Maintain good blood sugar control
- Control blood pressure
- Take regular exercise
- Eat a healthy diet
- Do not smoke.
Let’s say it loud and clear – a cataract is not a film or tissue that grows on the eye surface!
The eye contains within a clear natural lens situated just behind the iris, which is the coloured part of the eye. As we age, the lens structure changes; opaque areas develop and the lens starts to yellow. The process of cataract-formation is usually very gradual.
Cataract can be considered a normal ageing change and is found in 60% of people over 60 years of age and nearly all over 70.
Most people with early cataract are symptom free, but if the cataract develops significantly the symptoms include:
- Blurring of distance vision
- Difficulty reading, especially in poor lighting
- Glare, especially when night driving or with low sun.
Cataract surgery is a very low risk procedure that involves removing the eyes natural lens and replacing it with an artificial lens. The surgeons are very highly skilled and can complete the surgery in about 10 minutes under local anaesthetic.
If surgery is required in both eyes the worst eye is operated on first and then the second, when the first is fully recovered.
You will need to come for a sight test about six weeks after surgery as the spectacle lenses will need to be changed at this time so that you can fully appreciate the improvement in your vision.
ry eye is one of the most common and debilitating conditions we encounter in practice.
The symptoms of dry eye include:
- Feelings of dryness, grittiness or soreness, which get worse throughout the day
- Intermittent blurring of the vision
- Redness of the eyes
- Watering eyes, particularly when exposed to wind
- Eyelids that stick to the eye when you wake up.
There are two underlying causes for dry eye problems.
Not enough tears are made
This is generally caused by problems with the lacrimal glands that produce the tears and can be associated with conditions such as Sjogrens syndrome.
Plenty of tears are made but they evaporate too quickly
This type of dry eye is associated with eyelid problems such as blepharitis, which often results in dysfunction of the oil producing glands. The purpose of oil is to sit on top of the tear film and slow evaporation. Not enough oil results in fast tear evaporation and dry eye symptoms.
We need to know the cause of dry eye so that the appropriate action can be taken to increase the amount of tears in the eyes and/or to slow down the evaporation so they stay in the eyes for longer.
Blepharitis is a condition where the rims of the eyelids become inflamed. This can result in symptoms such as burning, soreness or stinging of the eyes, crusty eyelashes and itchy eyelids.
Blepharitis is often caused by a bacterial infection of the lids but can also be associated with other conditions such as seborrhoeic dermatitis (the same condition that causes dandruff) and rosacea (a skin condition that causes red blotches on the face)
There are no serious complications of blepharitis but sufferers have an increased risk of:
- Dry eye
- Lid cysts
Blepharitis cannot be cured but regular lid cleaning will greatly reduce the population of bacteria on the eyelids, which results in less symptoms and complications.
We stock a variety of cleaning solutions specifically designed to treat this condition that are highly effective but also kind to the eyes. But remember, your eyelids should be cleaned every day whether you have symptoms or not.
Eye Care Glossary
Defined as a characteristic of a lens that prevents the formation of a perfect image. Aberrations affecting the quality of images produce degraded sharpness, lowered contrast, distorted shape, and colour fringing.
Accommodation is the ability of the eye to change its focus from distant to close objects. The eye achieves this by altering the shape of the crystalline lens with the ciliary muscles.
Clearness of sight, as in visual acuity. The most common measure of visual acuity is the Snellen eye chart. Normal acuity is having 6/6 vision.
Ametropia is any imperfection in refractive state of the eye. Examples would be one with hyperopia (long-sightedness), myopia (short-sightedness) or astigmatism.
Defined as a difference in refractive power of the two eyes in which the variance is at least one dioptre of power.
A condition in which the surface of the cornea is not spherical. An astigmatic cornea causes light images to focus on two separate points in the eye, creating a distorted image and poor focus.
This is the clear fluid that flows between and nourishes the crystalline lens and the cornea.
Chromatic aberration (ie colour fringing)
This occurs when a lens fails to bring white light, with its colour components, to the same focus point simultaneously.
One of two types of specialised light sensitive cells (photo-receptors) in the retina that provides the ability to see objects in colour and at high resolution in the central field-of-view. Also, see Rods.
The turning of the eyes inward/outward so that they are aimed toward the object being viewed.
The cornea is the clear, dome-shaped ‘window’ at the front of the eye that covers the iris and pupil. The cornea plays an important role in vision because it provides approximately 70 percent of the eye’s light-focusing power. Contact lenses rest on the corneal surface.
This is the natural lens of the eye – located behind the iris -which helps focus rays of light on the retina. The original state of the lens is transparent, but the lens may become cloudy with age (cataract). The lens has the ability to vary its shape, thereby focusing on closer objects.
Defined as the measurement of the refractive power of a lens element, as a portion of a metre.
This is a condition in which light rays focus correctly on the retina, without using corrective lenses; same as 6/6 vision. An emmetropic patient requires no corrective spectacles to see at all distances.
Common term for hyperopia, or hypermetropia.
An eye disease characterised by the narrowing of one’s field-of-view and caused by the increased pressure within the eyeball. If not diagnosed and treated, glaucoma may lead to optic nerve damage, loss of visual field, gradual vision impairment and sometimes blindness.
Shortsightedness, essentially; the enhanced ability to see close objects and inability to focus on distant objects. A negative lens is required to achieve normal vision.
With age, we all lose our ability to focus on nearby objects (accommodation). In our eyes, the crystalline lens loses flexibility and our ciliary muscles weaken. This limits our minimum focusing distance. Presbyopes with 6/6 vision will need reading glasses; presbyopic myopes and hyperopes need bifocals.
Also known as Varifocals or All-Disatance Lenses, these are lenses of multiple zones of optical power that provide both near and far focusing ability. For spectacle lenses, these are the modern replacement/alternative to bifocals or trifocals.
Like the film in a camera, the retina (made of rods and cones) at the back of the eye receives images formed by the eye’s optical system, and sends impulses to the brain through the optic nerve.
Rods are one of the two types of specialised light sensitive cells (photo-receptors) in the retina. They provide both the ability to see objects in dim light (night-vision), and peripheral vision. However rods provide monochromatic images, ie black and white. This is why, in very low light, we see objects in shades of gray.
Common term for myopia.
This is the transparent, colourless gel-mass that lies behind the crystalline lens and in front of the retina.
Eye Disease Summary
The following sections contain information on various eye conditions, their symptoms and effects on your sight and what can be done to help.
A cataract is a clouding of the normally clear lens of the eye. It may vary in its severity from a small amount of clouding to dense areas of haziness. A cataract is usually an age-related condition, which disturbs the passage of light and prevents the eye from focussing correctly.
A cataract is caused by metabolic changes within the lens. These changes are very common with age. Cataracts may also be caused by injury, trauma, radiation, medication or other eye diseases.
How do cataracts affect sight?
The person with a cataract may have blurred vision, suffer from glare and find bright lights uncomfortable. Colours may not appear to be as bright and objects look dull.
The progression of cataracts varies between each individual and often between each eye in the same person. In some cases, the person affected can see well in the house but find vision is reduced by glare or at night.
Many people have mild cataract without noticing any great affect on their vision. In more severe cases when the day-to-day vision is causing problems and vision can’t be improved with a change of glasses, treatment is usually required.
In some cases a change of glasses may be beneficial. In more advanced cases, cataract surgery may be the best form of treatment. This procedure is usually performed under local anaesthetic on a day surgery or in-patient basis. Special lighting and magnifiers are also useful.
Age Related Macular Degeneration
Age Related Macular Degeneration (ARMD) is damage or breakdown of the macula. The macula is the part of the retina which allows us to see clearly and appreciate colour. It is the small spot (approximately 3mm) near the middle of the retina, which is responsible for the central part of what we see. The retina is at the back of the eye. It is made up of cells which are sensitive to light.
How does it affect sight?
In the early stages of ARMD, central vision is blurred and seeing at a distance or close work is difficult. The eye may still have good side vision, but blank spots appear in the centre. This makes reading, sewing or seeing faces difficult.
Other symptoms include: dimming of colour vision, difficulty in judging heights and distances, and some difficulty with tasks such as pouring tea. Sometimes only one eye loses vision, while the other eye may see well for years.
ARMD does not lead to total blindness. People with ARMD mostly retain good side vision. This means they can cope well with most daily tasks. The latest magnification devices can be very useful.
Who is susceptible?
Apart from some rarer forms, ARMD is not hereditary. The condition occurs most commonly in older people.
Diagnosis and treatment
An ophthalmologist can detect ARMD in its early stages. Laser treatment can be useful if the condition is detected early.
Special magnifying glasses, daily living aids such as needle threaders, large print books, proper lighting or a combination of these can help the person with ARMD to be independent and lead a normal life.
Recent research has shown some evidence that good diet can help limit progression of macular disease. In particular fruit and vegetables, containing high levels of antioxidants and pigments such as lutein, are important parts of the diet. Vitamin supplements are also available which are especially designed to supply these vital ingredients.
In some cases of wet macular degeneration, where the vision is lost suddenly, laser treatment can limit the damage. If you do notice a sudden lose of vision it is always vital to see an optometrist as soon as possible.
Glaucoma is the leading cause of preventable blindness in the UK, responsible for 13% of those on the blind register. It is estimated that about half a million people suffer from glaucoma in the UK alone; about half of these have the chronic form of the disease and in this group half remain undetected.
The eye is normally filled with intraocular fluid which constantly drains away and is then replaced. In the case of glaucoma, intra ocular fluid is not drained away properly, or it may be produced in large amounts. If this causes too much pressure in the eye, the optic nerve is damaged aqnd blind areas in the field of vision develop. Glaucoma tends to happen slowly, often with no noticeable changes until after the damage is done.
How does it affect sight?
In acute glaucoma the pressure rises very quickly and symptoms include pain, blurred vision and haloes around lights. In the more common chronic glaucoma, side (peripheral) vision is affected first. This can happen very gradually and may not be noticed until quite advanced damage has occurred. This is why it is important to have routine eye examinations even if you don’t think any changes have occurred.
Diagnosis and treatment
The good news is that most glaucoma cases can be treated. A painless examination is made to measure the pressure within the eye. The optometrist also views the
detailed check of your peripheral vision. Although damage cannot be reversed, treatment can prevent it from becoming worse. The longer high pressure remains in the eye, the more likely damage will occur.
Treatment aims to reduce the pressure by helping fluid to drain out of the eye, or by reducing the amount produced.
Eye drops are most often used to treat glaucoma, although sometimes laser and surgery are necessary. Glaucoma is a life-long condition which requires continual management to prevent loss of vision.
Who is susceptible?
Most cases of glaucoma occur in the older age group. If there is a family history of glaucoma, there is a higher risk of developing the condition. People over the age of 40 and those with a family history should have a regular glaucoma test. back of the eye to examine the optic nerve for any damage and may carry out a
This is caused by diabetes, although having diabetes does not necessarily lead to sight loss. Retinopathy affects the retina. The retina is at the back of the eye and is made up of cells which are sensitive to light.
Early diabetic retinopathy is sometimes the first indication of diabetes. If your optometrist sees changes to the retinal blood vessels during your eye examination, they may advise further checks with your doctor.
A network of blood vessels feeds the retina. Diabetes can cause blood vessels to break and this can interfere with vision. Blood clots and scars may form on the retina, blocking the light rays from nerve cells and interfering with their nutrition.
Complete loss of vision can occur when scar tissue develops at the back of the eye. This sometimes pulls and detaches the retina.
Prevention and treatment
Preventing diabetic retinopathy or its advancement is helped by correct management of diabetes and regular eye check-ups with an ophthalmologist. Laser light beams directed to the affected part of the retina may be used to seal leaking blood vessels.
Who is susceptible?
Diabetics with high blood pressure, pregnancy or prolonged poor diabetic management are considered to have a higher risk of developing this condition
What is it?
The eye ball is protected by a layer of tears which have antibacterial properties and keep the eyes lubricated and comfortable. In addition the tear layer provides a smooth surface for the refraction of the light as it enters the eye.
Dry eye occurs when some of the tear components are not produced in sufficient quantity. This can cause grittiness and irritation and also some blurring of vision – particularly is associated with computer use.
Bizarrely, one of the symptoms of Dry Eye is that the eyes produce more tears, resulting in your eyes streaming even more. You may ask – how can my eyes be dry, when they are running with tears? The answer is that your eyes are not producing tears of sufficient quality. Your body can detect this and stimulates the production of more tears.
Prevention and Treatment
Avoiding dehydration and dry working environments is helpful. If you work in modern air conditioned/ centrally-heated offices, remember to drink plenty of water during the day.
Usually tear supplements will be beneficial – these range from eye drops/gels to overnight ointments. Your optometrist can advise you on which is most suitable depending on your circumstances and symptoms.
Who is susceptible?
Dry eyes are more common in the elderly. In modern dry environments, however, it can affect people of any age – particularly contact lens wearers and people working on computers.