Amblyopia is a visual disorder in which an eye fails to develop normal visual acuity. The condition usually results from poor eye co-ordination, from having a turned eye, or from having one eye which requires a far greater spectacle prescription than the other.
When detected early enough, patching, vision training and lenses may help to improve the vision in an amblyopic eye. Amblyopia due to a turned eye sometimes requires surgery to improve eye alignment.
Astigmatism is an out-of-roundness of one or more surfaces in the eye’s optical system.
An eye with no astigmatism is spherical in shape, like a marble. On the other hand an eye with astigmatism has a distorted shape, slightly like a grape.
In lesser degrees this can cause strain and discomfort after visual concentration; while in higher degrees astigmatism causes images at all distances to be distorted or blurred.
Cataract is an opacity or clouding of the lens inside the eye, then distorting the light as it enters. Cataract is often confused with pterygium but cataract cannot be seen on the surface of the eye.
Symptoms of cataract may include a gradual painless decrease in clear vision, hazy vision, increased sensitivity to glare, and even double vision.
Special tints or filters can often improve vision and UV protection can help to slow development of this condition.
The eventual “cure” is surgical removal of the lens with cataract and replacement with an artificial lens (intra-ocular lens implant).
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 acquired condition as a result of some diseases or injuries.
The abnormality is sex linked, recessive, and carried on 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, about 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.
Eye Misalignment occur when the eyes do not align or focus together as a team. This improper control of the eye muscles can result in crossed-eyes, poor focussing ability, or simply discomfort and headache from the extra effort required to maintain alignment.
Common remedies are vision training, prisms, therapeutic spectacles, bifocal or progressive lenses.
Glaucoma is a disease where the pressure within the eye is typically increased (although not always). This can damage parts of the eye, and if left untreated may result in blindness.
Many times the symptoms are not noticeable until damage to the eye has already occurred. Diagnosis consists of having regular eye examinations which include a pressure measurement (usually every 2 years for patients over 40), to enable early detection of possible problems.
Hyperopia (long-sightedness) causes a person to see clearer at far than at near.
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.
Myopia (Short-sightedness) 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 inside the eye.
Myopia tends to first develop during adolescence as the eye grows to full adult size. Myopia occurs either due to hereditary factors or due to environmental stress and a subsequent spasm of the eye focussing muscles.
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.
Keratoconus is a condition where the front surface of the (cornea) becomes thin and stretched near its center, causing it to bulge forward into a conical shape. As a result vision becomes distorted. This distortion of vision is due to the development of myopic astigmatism. Initially glasses are used to provide clear vision however as the condition advances the cornea becomes highly irregular and vision is no longer adequately corrected with glasses. At this point in time specially designed gas permeable contact lenses can be fitted. These contact lenses allow tears to fill a gap between the irregular corneal surface and the smooth regular inner surface of the lens eliminating the distortion of the conical cornea.
Our practice has a specialised instrument called a corneal topographer. The topographer provides a 3D map of the cornea which is useful for diagnosing keratoconus, monitoring progression and designing custom made contact lenses.
If you have keratoconus, or if you’re concerned that you might have it and require an eye examination, please call us for an appointment on 9528 6991.
Macular Degeneration (MD) is a disease associated with aging that gradually destroys central vision. Central vision occurs at the macula on the retina, at the back of the eye. Because it is the central part of vision, it is needed for seeing objects clearly and for common everyday tasks such as reading and driving.
In some cases, MD advances so slowly that people fail to notice the gradual deterioration of their vision. In others, the disease progresses faster and may lead to a permanent loss of central vision.
While there is presently no cure for Macular Degeneration, there are steps that you can take to prevent or slow the progress of the disease.
MD is present in 15% of people between the ages of 70-75 and is now the leading cause of blindness and severe vision loss in Australia.
Presbyopia is a gradual loss in the focussing 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 lens, so that by the early 40’s it does not respond as well to the muscles intended 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.. 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 the newer progressive lenses.
Pterygium is a triangular growth of degenerative tissue on the white of the eye (sclera), usually on the nasal side, that may extend 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. Treatment is by eliminating the irritation with protective eyewear, eye-drops or surgery.
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. A full eye examination will determine the cause and whether any follow-up is needed.