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About Your Eyes

Why regular eye examinations are so important

Your eyes are remarkably complex and so important in everything you do. Minor changes can have a marked effect on vision and comfort, and there are a number of changes that can occur.

As we age, there is an increasing chance of eye problems developing. Many of the vision changes caused by eye disease occur slowly, often over a period of years and sometimes without obvious signs or symptoms. Regular check-ups make detection more likely and enable prompt treatment, giving a better chance of curing or controlling any eye disorder.


Astigmatism

Astigmatism is present in varying degrees in most eyes. This happens because the lens inside the eye or the cornea in front of the eye is toric in shape, where it has unequal curves like a rugby ball, rather than a round soccer ball. Astigmatism can occur by itself or in conjunction with myopia, hyperopia or presbyopia. The result of astigmatism is that outlines of objects seem more blurred or shadowed. Astigmatism can cause blurry vision, tired eyes, eye strain, headaches and glare intolerance. Prescription lenses for astigmatism are available in glasses and contact lenses.

Myopia

Myopia if often referred to as short-sightedness. People with myopia are more likely to find vision is clear for near objects and blurry for objects at distance. Myopia can be corrected with the help of prescription spectacle lenses and contact lenses.

Hyperopia

Hyperopia is sometimes called long-sightedness. This occurs when the cornea is flat or the length of the eye is shorter than normal. The hyperopic eye has to exert focus effort with the crystalline lens (called 'accommodation') to keep an object clear. As we get older it becomes increasingly difficult to accommodate or to maintain this effort. Blurring may occur at all distances, but is more pronounced for near objects, and is sometimes intermittent. The extra effort exerted by the eyes may also cause eye strain or headaches. Prescription lenses in glasses and contact lenses will assist hyperopia.

Presbyopia

Presbyopia is a process that causes the "auto focus" lens in our eyes to become less flexible with age. This makes it harder to adjust focus from one distance to another. In virtually all cases, if you see clearly at distance with both eyes, sooner or later, you will start to have difficulty focusing on small print at a normal reading distance. This often begins sometime in your forties. The prescription lenses to correct for close work are additional to those you may need at long distance. Reading, bifocal or progressive prescription lenses will assist with presbyopia. Your lenses may need to be gradually increased in power as the eye changes. It is important to stress that the use of reading lenses does not accelerate or retard this normal process that occurs. There are also contact lens options to assist with presbyopia.

Eye Coordination Problems

Each of our eyes has 6 muscles to move the eye in all directions and to align it with the other eye. Ideally the muscles in both eyes work together and in unison to keep our eyes aligned. If they don't, it may lead to eye strain, tired eyes, concentration problems and even double vision. Such eye co-ordination and alignment problems are called phorias or tropias. With a tropia, (sometimes referred to as a squint) the eyes, for a variety of reasons and causes, do not work together and point in different directions. This can cause double vision, and the brain may suppress the image of one of the eyes to give single vision. In young children this can lead to the vision not fully developing in the suppressed eye (amblyopia) and early investigation and treatment is essential. Most of us have a small amount of binocular imbalance and we can overcome this easily. If not, then additional effort is required to keep the eyes working together, and this can lead to eye strain, concentration problems and difficulty with reading. There are a number of other associated focusing and coordination problems that can affect the performance and efficiency of our visual system. Your optometrist can detect these problems and treatment may be in the form of glasses and/or eye exercises.

Floaters

Floaters (or spots) are particles which float inside the eye and cast shadows on the light sensitive tissue at the back of the eye (the retina). Usually these are nothing more than a nuisance. However, floaters can result from eye disease or injury and do need assessment by your optometrist. This is especially so if they are accompanied by repeated flashes of light in the peripheral vision. Most people see floaters some time during their life. As we get older, the thick fluid ( vitreous) inside the eye becomes more liquid, allowing particles to move more freely and these cast shadows on the retina.

Glaucoma

Glaucoma is a disease of the eye that can occur at any age, but it is more common as we grow older. Glaucoma is one of the leading causes of blindness in New Zealand. When diagnosed early, vision loss from glaucoma is usually controllable with ongoing treatment.

In many people this damage is due to increased pressure inside the eye. Usually the damage will be caused by poor blood supply to the fibres of the optic nerve or problems in the health or structure of the nerve itself.

Uncontrolled glaucoma will initially cause blind spots or reduced vision in the peripheral vision. People often don't notice these until considerable damage is caused. Although damage usually progresses very slowly, it is irreversible. Treatment cannot recover vision that has already been lost - but usually can slow down or halt the damage process.

For some people there is a sudden and large increase in fluid pressure inside the eye causing symptoms which include blurred vision, severe pain, coloured rings around lights, and even nausea and vomiting. If this occurs it is important to seek attention immediately to avoid permanent loss of vision.

Glaucoma can run in families but can occur to anyone. It is often symptomless initially and most undetected patients are unaware they have the disease until it is an advanced stage. Regular eye examinations are the best way to detect glaucoma. These include your optometrist testing for glaucoma by examining the optic nerve at the back of your eye, checking your eye pressure, and assessing your peripheral vision.

Diabetes and your eyes

One of the most distressing and difficult complications of diabetes is reduced vision. Diabetes is a leading cause of preventable blindness in the adult population. However you can help save your sight by:
  • Good control of blood glucose levels
  • Treatment of general medical conditions such as high blood pressure and /or abnormal cholesterol levels
  • Regular eye examinations
  • Checking with an optometrist or ophthalmologist about the possibility of more frequent examinations if you are pregnant as pregnancy poses additional risks

Children's Vision

Children's Vision Care

At Tarbutt Optometrists we are here to help with any concerns you have about your child's vision, please feel free to call us to make an appointment or for advice on their vision.

Why is vision so important?

Because 80% of children's learning is done visually. Reading, writing, white/blackboard work, computers - are all hard work if you cannot see clearly. It stands to reason that having clear comfortable vision is necessary for a child to learn successfully. So many of the day-to-day learning tasks at school require seeing quickly and using visual information.

Is it OK so long as the child can see the white/blackboard?

No - not necessarily. The white/blackboard may still look clear and sharp to a child who is having problems with close vision tasks and the child that doesn't see the white/blackboard clearly may not even think to complain because the board has always looked that way. Unfortunately, a simple distance vision check for the white/blackboard does not detect a variety of other problems which affect reading and focus.

What about eye coordination skills?

Clear eyesight helps with all learning tasks, but for close vision work, and particularly reading, other visual skills are needed. Children must have a variety of scanning, focusing, and visual coordination skills for learning and for understanding print. If these skills have not developed well, learning is stressful and difficult.

Are learning difficulties and poor vision related?

Many children who have learning difficulties, especially with reading, in fact have focusing errors or poor eye muscle coordination, which creates stress or fatigue with close work. Children with these vision-related learning problems often have excellent distance eyesight. Consequently, their near vision problems, which are more likely to affect learning, will often go undetected as standard school screening only tests the clarity of distance vision.

What can parents and caregivers do?

Parents, caregivers, and teachers should consider undetected visual problems as a contributing factor if learning is not keeping pace with other indicators of ability and intelligence. This is particularly so if symptoms of visual stress are present. A full and thorough eye examination by an optometrist is the most effective way of detecting and eliminating the possibility of visual problems.

What do our Optometrists examine?

• Distance vision (visual acuity): Your child should be able to see well in the distance with both eyes.
• Near vision: The ability to see close objects comfortably and clearly is important for both learning and play.
• Changing focus (accommodation): Changing focus from distance to near and back again is a big part of classroom learning. Your child needs to be able to do this comfortably and quickly.
• Aiming the eyes (fixation): Double vision or confused images can occur if the two eyes do not aim together. This can seriously affect learning and play.
• Eye movement and coordination skills (saccades and tracking): In order to see well, the eyes need to move together in a smooth and precise fashion. This is very important when following a moving object. The eyes also need to be able to jump immediately from one object to another, such as word-to-word or line-to-line in reading.
• Peripheral vision: Peripheral vision is important so your child is aware of what is happening around them. This is important in classroom situations, in sport and in play.
• Colour Vision: Good colour vision is not a vital function, but is important in some career choices. Boys are affected more often than girls.
• Eye Health: A thorough external and internal examination of your child's eyes is necessary to identify any possible underlying eye health problems.
• Eye Drops: Your optometrist may decide it is necessary to put drops in your child's eyes. These drops relax the focusing system and can allow a more reliable testing of any focusing problems. The drops also make the pupils larger than normal. The effect lasts only 3-4 hours.

If you child has more than one of the below symptoms we advise you call us for an appointment with one of our optometrists:

• Headaches
• Complains of not seeing clearly
• Rubs eyes
• Burning or itchy eyes
• Shuts one eye when reading
• Tilts their head at an angle to the book while reading
• Holds a book very close
• Moves the head sideways when reading
• Omits small words when reading
• Poor concentration
• Copies incorrectly from the black/white board
• Loses place when copying from other written material
• Misaligns digits in columns of numbers
• Avoid close work
• Becomes tired after close work
• Blinks excessively when doing near vision work, but not otherwise
• Reverses letters or numbers
• Writes up or down hill, with irregular letter or word spacing
• A history of eye problems in the family, especially in brothers or sisters

Senior Vision Care

As we get older, many aspects of our vision change. Because of this, it is important to make regular visits to your optometrist, so your vision can be monitored. We are here to help with any concerns you may have about your vision.

Two common eye conditions that cause vision deterioration as you age are Cataracts and Macular Degeneration. These both affect your eyes by substantially reducing your vision, however, both affect your vision very differently:

Cataracts - What are they?

Cataracts occur when the lens inside your eye becomes increasingly opaque resulting in 'misty' or 'foggy' vision.

What are some effects of cataracts?

  • In the early stages someone may notice a 'film' in their everyday vision.
  • Things that used to look black and white now look grey and colours are perceived as dull.
  • As cataract becomes more advanced, vision becomes foggy, less detail is seen, reading can be slower, television isn't perfectly clear and driving becomes difficult when driving into the sun, at this stage new spectacles will not restore 'normal' vision.

Can cataracts be helped?

Usually the answer is yes. Corrective surgery removes the cataract (the cloudy lens), and an artificial lens (intra-ocular lens) is put in its place. Most people will benefit from surgery. Your overall health and any other eye conditions you may have will be considered before a decision is made to operate. Your optometrist will refer you to an ophthalmologist (eye doctor) to confirm that you will benefit from having your cataracts removed.

Is it time for you to have your eyes examined?

Macular Degeneration - What is it?

Macular egeneration is also know as age-related maculopathy. As our eyes age, the retina (lining the inside of the back of the eyeball) starts to deteriorate, making clear vision more difficult. This is particularly true of the most sensitive part of the retina, the centrally located macula. When this region starts to atrophy, sharpness of vision is lost and this can lead to difficulty with reading, and often, the need to give up driving.

Does Macular degeneration cause blindness?

Macular degeneration may cause vision problems, but it rarely ends in total blindness. The condition tends to progress slowly with only some aspects of vision being affected. Peripheral vision is not affected, but a loss in detail when looking directly at an object can be an early sign of Macular degeneration. Other early symptoms of macular degeneration usually involve an awareness of blurring in the central vision; sometimes vision may become distorted. For instance there might appear to be a 'kink' in an otherwise straight doorframe. This could require urgent assessment.

Who gets Macular degeneration?

Many people who are aged 70 and over have some macular degeneration. If there is a family history of Macular degeneration there may be an increased risk. In addition, people with certain medical conditions (e.g. diabetes) may be more likely to develop macular degeneration. Its is therefore important to make sure you have regular health check-ups. Smoking is a known risk factor for macular degeneration.

What treatment is available?

For many cases of macular degeneration no treatment is currently possible. We may help with special spectacles or other visual aids to help with reading. Laser treatment may be an option for some people with macular degeneration and new therapies including micro-surgery and photodynamic therapy are looking promising for the future. We will be able to advise you on this and provide referral. A healthy diet that includes dark green leafy vegetables is thought to help maintain macular health.

Some suggestions:
• Regular eye examination will help you make the most of your vision.
• Continue to enjoy reading and the like - avoiding close work will not 'save' your eyes.
• Have good lighting when doing close work, preferably with a reflector lamp to illuminate your task.
• When outdoors, wear a hat with a brim to reduce unwanted glare from the sky.
• Sunglasses may be very helpful in bright conditions.
• Ensure you have an good diet with plenty of fresh vegetables and fruit.
• Regular medical examinations are essential to ensure that your health is normal.
Both cataracts and Macular Degeneration are more likely to develop as we get older. For many people there is only mild loss of vision with either of the conditions. If you notice any of the above we recommend you make an appointment with one of our optometrists for an eye evaluation as soon as possible. Any sudden loss of vision is unlikely to be due to cataract or macular degeneration and such an event requires immediate attention.

Glaucoma - What is it?

Glaucoma is an eye disorder in which the fluid pressure inside the eye causes progressive damage to parts of the optic nerve. The pressure usually increases when there is inadequate drainage of fluid from inside the eye. A gradual but permanent loss of vision occurs unless the condition is treated.

There are three main types of glaucoma:

Acute Glaucoma

when a rapid blockage of the drainage system occurs. With little or no warning, the eye becomes red and very painful, and misty vision may include halos around lights

Chronic Glaucoma

when the pressure slowly increases over several months or years. No symptoms are present in the early stages, and severe loss of vision may occur before a person realises that something is wrong

Secondary Glaucoma

results when injury, inflammation or tumour blocks the drainage canals

How does Glaucoma affect my sight?

If the pressure is raised for a period of time, some fibres of the optic nerve which conduct impulses from light sensitive cells of the retina to the brain are destroyed. Because the loss of vision occurs slowly, and away from the direct line of clearest vision, a person with glaucoma may not notice any changes to their sight until a considerable reduction to the field of vision has occurred. Without treatment, this loss continues until the eye is blind.

How is Glaucoma detected?

We will check for glaucoma as part of a regular eye examination. Tests include assessing the appearance of the optic nerve head, measuring the pressure in the eye, and analysing the complete field of vision. If any signs of glaucoma are detected, you will be referred to an ophthalmologist (eye specialist) for further evaluation.

Can sight which is lost be regained?

No - treatment aims to prevent any further loss of vision. Early diagnosis is essential - vision already lost can not be regained.

Who gets Glaucoma?

Anyone may develop glaucoma, but the risk increases as age increases, and the risk is higher if close relatives have glaucoma. About 2 in 100 people over the age of 40 have glaucoma. By age 60 the rate is 3 people in 100, rising to 5 in 100 of people over 80 having glaucoma.

Everyone, especially those over 40, should have their eyes examined regularly to check that no eye health problems are present or developing. A thorough optometric examination will ensure that you continue to have efficient, comfortable vision and healthy eyes. Do not forget that most people begin to have difficulty with near vision in their forties. This is a normal ageing process solved by using spectacles to help with close work.

Diabetes

How does Diabetes affect my sight?

Diabetes may cause damage to the retina, and produce changes called diabetic retinopathy. The retina is the delicate layer of blood vessels and light sensitive cells positioned at the back of the eye similar to the film in a camera. Images we see are formed on the retina itself, converted into electrical impulses, and pass from the retina to the brain along the optic nerve.

The central part of the retina is called the Macula. This part is the most sensitive and allows us to see fine detail. The rest of the retina sees the less well defined images but gives us peripheral visual awareness, movement sensation and helps us see at night. If the retina is damaged by diabetic retinopathy our vision can be reduced.

Diabetic retinopathy is a disease of the retina. The early symptoms are quite common amongst those with diabetes. Often, these changes are minor (non sight threatening) but require regular monitoring.

In some cases, the early signs of diabetic retinopathy progress to a more severe form of eye disease called Proliferative retinopathy. If untreated, 50% of those affected will suffer serious visual loss. This stage is marked by the growth of very fine delicate new blood vessels (Neovascularisation) which bleed very easily. This bleeding causes varying amounts of visual loss.

Sometimes the bleeding results in the formation of scar tissue which contracts and pulls away the retina (retinal detachment). This is a serious sight threatening condition and must be treated promptly.

Examination of the retina is a simple procedure and usually involves drops which dilate your pupils so that the retina can be directly examined and photographed using modern digital cameras.

The drops will blur your near vision and make your eyes more sensitive to light. You should bring a pair of sunglasses with you. Although some people can drive afterwards, we recommend either leaving your car behind or arranging a driver.

Glaucoma

Glaucoma is a disease of the eye that can occur at any age, but it is more common as we grow older. Glaucoma is one of the leading causes of blindness in New Zealand. When diagnosed early, vision loss from glaucoma is usually controllable with ongoing treatment.

In most people this damage is due to increased pressure inside the eye. In other patients the damage will be caused by poor blood supply to the fibres of the optic nerve or problems in the health or structure of the nerve itself.

How does Glaucoma affect sight?

Uncontrolled glaucoma will initially cause blind spots or reduced vision in the peripheral vision. People often don't notice these until considerable damage is caused. Although damage usually progresses very slowly, it is irreversible. Treatment cannot recover vision that has already been lost - but it can at least slow down or halt the damage process. Glaucoma can run in families.

For some people there is a sudden and large increase in fluid pressure inside the eye causing symptoms which include blurred vision, severe pain, coloured rings around lights, and even nausea and vomiting. If this occurs it is important to seek attention immediately to avoid permanent loss of vision.

A full vision examination at Tarbutt Optometrists usually takes at least 30-45 minutes. This period of time is needed to perform all the tests necessary to thoroughly assess your eyes, their health and their visual efficiency. Sometimes additional tests are required and a second appointment may be needed for these.

During your examination a health history will be taken. It is important for you to provide all information, regardless of how insignificant you might think it is.

Depending on the reason for your eye examination, tests may be performed which assess:
  • Eye health
  • General physical health
  • Clarity of vision
  • Colour vision
  • Near focusing ability
  • Eye muscle co-ordination
  • Glaucoma
  • Cataract and macula function
  • and other tests appropriate for each individual.
Following the examination, your optometrist will fully explain the results and discuss their recommendations and answer any questions you may have. If your optometrist finds any sign of eye disease or of general health problems, arrangements may need to be be made for you to see an ophthalmologist (an eye doctor) or your GP.