Frequently Asked Questions
Frequently Asked Questions
What are the symptoms of vision problems?
Following is a partial list of symptoms in children and adults which indicate the need for a complete vision analysis:
• Headaches, nausea or dizziness after visual concentration
• Blurred or double vision at any time
• Crossed or turned eyes
• Blinking or eye rubbing after visual concentration
• Dislike or avoidance of close work
• Short attention span
• Placing head close to book when reading or writing
• Frowning while looking at the TV or blackboard
• Difficulty reading small print
• Difficulty adjusting focus between near and far objects
What is Myopia (short-sightedness)?
Myopia is a condition in which near objects are seen more clearly than objects which are far away.
The main symptom is blurred distance vision. Short-sighted people often report difficulty distinguishing details on road signs and scoreboards.
Another common symptom is "squinting" the lids together in an attempt to see clearer. This works by narrowing the aperture they are looking through and therefore reducing the size of the blur circle on the retina at the back of the eye.
Myopia tends to first develop during adolescence as the eye grows to full adult size. Myopia occurs due to a combination of hereditary factors and environmental stress resulting in the eye growing longer or focusing light more than it should.
Myopia is corrected with either contact lenses or spectacles. Since these lenses are thickest at the edge, new spectacle lens technologies have been developed to produce thinner and lighter lenses.
What is Hyperopia (long-sightedness)?
Hyperopia causes a person to see clearer at far than at near. Although in some circumstances hyperopia can reduce the clarity of distance vision as well.
Extra effort is required to try to clear the focus at all distances, resulting in eye strain and fatigue. This "strain" can manifest itself as headaches after close work, blurred near vision, tired eyes, difficulty adjusting focus from distance to near and near to distance, avoiding close work and short attention span for near tasks.
Common symptoms are associated with tasks which require continued visual concentration. It becomes a problem to maintain a clear focus on near objects, causing headaches and tired or aching eyes.
In some age groups a prescription for hyperopia often works to relieve the strain, rather than clearing the vision.
When the level of hyperopia is very high, or when a person with hyperopia is over 40 (see presbyopia), it may also affect the clarity of their distance vision as well as their near vision. Full-time spectacle wear may become necessary.
What is Astigmatism?
Astigmatism decribes the shape of the optical surfaces of the eye. The cornea of an eye with no astigmatism is spherical in shape, like a marble. On the other hand the cornea of an eye with astigmatism has a distorted shape, slightly like a grape.
An eye with regular astigmatism has a different optical power vertically than horizontally. This means that vertical lines are focused at a different point to horizontal lines, leading to a generalized blur. This can be in addition to either long or short sightedness. An astigmatic (or toric) correction is easily incorporated into a spectacle prescription. These lenses have a different power vertically than horizontally to correct for the differences in the eye.
It is also possible for the eye to have irregular astigmatism. This is caused by the eye having multiple different powers across its optical surfaces in an irregular pattern, and occurs in conditions such as keratoconus. Unfortunately spectacle lenses are unable to correct irregular astigmatism and these patients require a specially fitted, customized hard contact lens to correct their vision.
In small degrees regular astigmatism can cause strain and discomfort after visual concentration, while in higher degrees astigmatism causes images at all distances to be distorted or blurred.
What is Presbyopia?
Presbyopia is a gradual loss in the focusing ability (accommodation) of the eye and is part of the normal vision changes we all experience.
This is caused by a natural hardening of the eye’s internal lens, so that by the early to mid 40's it does not respond as well to the efforts to change the focus of the eye. As a result, people in this age group start to have difficulty with near tasks like reading small print, threading a needle, etc. A common complaint is that they feel “their arms aren’t long enough”, as they need to hold objects further away to maintain focus. This is especially true at the end of the day when lighting levels are poorer and the individual is more likely to be tired.
Correction consists of reading spectacles, bifocals or progressive lenses.
Could my child have undetected vision problems?
With one in 4 children at risk of falling behind academically and socially due to undetected vision defects, parents should be vigilant in monitoring their child’s visual development.
Optometrists urge parents to be on the look out for symptoms of vision problems particularly when children are reading, completing homework or watching television. Excessive blinking, squinting or rubbing of the eyes, complaints of headaches, trouble concentrating or holding books very close when reading are just some of the symptoms of a possible vision problem. These problems often escape detection in basic vision screenings.
The upcoming school holidays would be an ideal time to make an appointment with Abernethy Owens Optometrists for an eye examination.
What is Ortho-k?
If you are short sighted (myopic) you are probably aware of three alternatives to regain clear vision: spectacles, contact lenses or refractive surgery. Now there is a safe, convenient and non-surgical alternative, Ortho-K. The freedom and convenience of clear vision without spectacles and without the need for expensive and irreversible surgery can be yours.
Ortho-K or Orthokeratology describes the gentle reshaping of the cornea while you sleep. Upon waking, your corneas are the correct shape to accurately focus light, enabling you to see clearly without assistance. The reshaping is achieved using special contact lenses which are removed upon waking.
Contact Abernethy Owens to find out more.
What is Amblyopia (lazy eye)?
Amblyopia is a reduced best corrected vision, generally in only one eye. The condition usually results from poor eye co-ordination, from having a turned eye or after having one eye which requires a far greater lens correction than the other eye.
The reduced vision occurs because, for one or more of the above reasons, one eye is being used less than the other during the critical period of brain development in childhood. As the brain is receiving less visual input from one eye it does not develop the ability to use this eye properly. When detected early enough, patching, vision training and lenses may help to reverse or prevent permanent damage to the vision.
What are binocular vision problems?
Binocular vision problems result from the eyes failing to align or focus together as a team. This improper control of the eye muscles can result in crossed-eyes, eye strain, poor focusing ability, or simply discomfort and headache from the extra effort required.
Common remedies are vision training, prisms, therapeutic spectacles, bifocal or progressive lenses.
What is Glaucoma?
Glaucoma is a disease where there is progressive damage to the optic nerve of the eye. This is sometimes associated with a raised fluid pressure within the eye (Intraocular pressure), although it is also possible to have glaucoma in the setting of a normal intraocular pressure . Initially glaucoma results in a loss of peripheral vision in a specific pattern. As the disease progresses, this vision loss progresses, and if left untreaded eventually leads to blindness.
Many times the symptoms of glaucoma are not noticeable until severe damage to the eye has already occurred. Diagnosis consists of having regular eye examinations which includes a careful examination and monitoring of the optic nerves as well as intraocular pressure measurement and visual field screening. Early detection is extremely important so that treatment can be initiated in order to prevent further vision loss. For this reason optometrists recommend regular eye examinations at least every 2 years for patients over the age of 40, and more regularly for people at higher risk of developing the disease (such as those with a family history of glaucoma).
What is a Cataract?
A Cataract is an opacity or clouding of the lens inside the eye, which scatters and distorts the light as it enters the eye. Cataract is often described as a ‘growth across the eye’ however it is actually a result of the lens within the eye becoming denser and therefore less transparent to light.
Symptoms of a cataract may include a gradual painless decrease in clear vision, hazy vision, increased sensitivity to glare, and even image doubling.
The eventual "cure" is surgical removal of the cataract and replacement with an artificial lens (intra-ocular lens implant).
What is a Pterygium?
Pterygium is a triangular growth of degenerative tissue on the white of the eye (sclera), usually on the nasal side that extends onto the clear window of the eye called the cornea.
A pterygium results from irritation due to long term exposure to ultra-violet light (UV), wind, glare or dust. A Pterygium can be treated by eliminating the irritation with protective eyewear, eye-drops or surgery. UV protection such as a hat and sunglasses should be worn when outside in order to minimize the risk of developing a pterygium. In some cases when a pterygium is actively growing across the cornea surgery is required to remove this tissue.
What are spots and floaters?
Spots and floaters are semi-transparent specks of natural materials inside the eye, which sometimes can be seen floating in the field of vision. Some patients comment that they look like cobwebs or threads, and most usually notice floaters when looking at a bright clear background like a ceiling or plain coloured wall.
They can be caused by debris left over from before birth, injury or eye disease. Although most of the time floaters are nothing to be concerned about, the sudden appearance of new floaters particularly when associated with flashes of light should be examined promptly to rule out a retinal tear or detachment. A full eye examination will determine the cause and whether any follow-up or treatment is needed.
What is Refractive Surgery?
Refractive surgery describes a group of procedures where surgery is used to correct the focus of vision instead of spectacles or contact lenses.
The most modern techniques use computer controlled lasers to remove a layer of the cornea (window at the front of the eye) and to reshape it to correct vision. Our practice is involved in the assessment of suitable candidates, referral of patients for the procedure and follow up after the surgery.
Refractive surgery is best suited for patients who wear spectacles or contact lenses all the time. Most patients do not need spectacles for general wear after the surgery but it is likely that a prescription will often be needed for fine work or reading as focusing problems (presbyopia) develop naturally in the early 40's. Those with presbyopia or "ageing eye", which often occurs in the early 40’s, cannot generally have this problem treated by laser surgery, although in some cases monovision laser treatment may be used for one eye only.
Originally, laser surgery could only correct short-sightedness. Now it offers hope to those suffering astigmatism (distorted vision) and long-sightedness. Laser surgery gives speedy results with minimal pain. But this procedure is not suitable for everyone. If you are under 18 years old, pregnant, or have had changes to your prescribed corrective lenses in the past year, we usually do not recommend laser surgery.
Cost is an important factor. Laser surgery can be expensive and is not covered by Medicare or any other private health fund (though in some cases it may be partially tax deductible). Most laser clinics offer finance plans or interest-free terms.
Reputable eye surgeons emphasise that not all laser patients will attain 20/20 vision. This depends on various factors, including the severity of the patient’s original vision problem. Some patients may still require glasses or contact lenses after laser surgery. As with any surgery there are risks associated with refractive surgery. It is important to weigh up the benefits vs the risks before undergoing any such procedure.
What is Colour Vision and Colour Blindness?
A routine part of our eye examinations is an assessment of colour vision, especially for children.
Colour blindness is almost always inherited, although it can be an acquired condition as a result of some diseases or injuries.
The most common form of colour vision deficiency is a red-green defect which results from a recessively inherited abnormality in the X chromosomes. This means that males need only have their one X chromosome affected to be colour blind while females must carry the condition on both their X chromosomes to be colour blind. If females have it only on one X chromosome they will carry the condition but still have normal colour vision themselves.
As a result, approximately 8% of males and 0.5% of females have colour vision deficiencies. Almost all colour deficient people do see most colours but they will have difficulty identifying particular ones, confusing certain shades of red and green for example.
As children, few of these people will be aware that they have a colour vision deficiency but the detection of these problems is important, especially when career choices are affected.
What is Retinopathy?
Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease's affect on the retina is the main threat to vision. Most patients will develop diabetic changes in the retina after approximately 20 years of the disease, although some will much earlier. The effect of diabetes on the retina is called diabetic retinopathy.
In this condition the small blood vessels in the retina become weakened and leak, forming small haemorrhages. The leaking of the vessels often leads to swelling in the retina and decreased vision. If untreated circulation problems can occur in these vessels and the retina becomes deprived of oxygen. This leads to death of the cells in the retina and a permanent loss of vision.
The affect of diabetic retinopathy on vision varies widely depending on the stage of the disease. Some common symptoms of diabetic retinopathy are listed below, however, diabetes may cause other eye symptoms:
• Blurred vision (this is often linked to blood sugar levels)
• Patchy vision
• Loss of contrast
• Floaters and flashes
• Sudden loss of vision
If you are diabetic the National Health and Medical Research Council recommends yearly eye examinations so that related eye problems can be detected and treated as early as possible. At our practice we perform detailed dilated fundus examinations on all diabetics. The retinal vascular changes that occur in diabetic retinopathy occur in all of the organs of the body, including the kidneys, liver, brain and extremities. However the retina is the only vascular bed in the body that we can directly visualise. Therefore any changes detected in the eye give a good indication of changes that may be going on in other parts of the body. Any signs of diabetic changes are communicated to your general practitioner or diabetes specialist. Anything requiring treatment will be referred on to an ophthalmologist.
What is "normal" in my vision?
It is normal for most eyes to be long-sighted at birth. This usually reduces as the eye grows to full adult size during adolescence. It is then in the teens that short-sightedness tends to develop, if at all.
After a relatively stable time in the twenties and thirties another significant time for change begins in the forties. This involves a gradual loss in the ability to finely focus the lens inside the eye. The result is a totally normal and expected change called "presbyopia", which continues into the sixties.
After sixty, the eye will tend toward less long-sightedness or more short-sightedness as the inner part of the eye lens hardens. Sensitive vision drops and the retina's fine discrimination of colours is dulled. By the age of seventy most eyes show signs of cataract and the older, harder, clouded eye lens scatters light so that glare often becomes more of a problem.
How often should I have my eyes examined?
Your Optometrist will advise you of the interval between your full eye and vision examinations which is appropriate for your vision and eye health needs. This time interval does vary for different situations, so we contact our patients when their next routine check is due. Changes in vision and eye health are often quite slow and subtle, and can easily go unnoticed if not checked regularly.
Of course if a problem arises sooner, please make an appointment so that we can assess the situation for you.