Myopia

Short sight, occurs when the eye focuses light too quickly resulting in the image being in front of the retina. This usually occurs when the eyeball is too long. This causes near vision to be clear but blurred at a distance.

Myopia can occur at any age but often begins in childhood, during the teenage years, or early twenties.

Spectacles, contact lenses or refractive surgery may correct Myopia. 

Hyperopia

Long sight, results in blurred near vision and in extreme cases distance objects may also be affected.

Hyperopia occurs when the eyeball is either too short or the lens of the eye is not curved enough.

Those with Hyperopia are required to make a greater effort than normal to focus. This may then cause the eyes to turn in resulting in crossed eyes and sometimes a 'lazy eye' may develop.

A child with Hyperopia might get more tired when reading or writing or may suffer headaches when copying from the blackboard. They may experience blurry vision at times, more often when doing close work.

With age, the focusing mechanism of the eye becomes less flexible requiring reading glasses earlier than is normal in middle age

Spectacles and contact lenses are prescribed to relax the eyes and provide more comfortable clear vision.

Presbyopia

'Middle-aged sight'. There is a gradual deterioration in the ability of the eyes to focus at closer ranges, as we get older. This occurs as a result of reduced flexibility of the eye’s natural lens. Symptoms such as difficulty reading and arms not being long enough generally appear in the forties and sometimes tiredness and headaches occur more often.

At this stage some help is required in the form of reading glasses, or for those who already wear spectacles, there are multi-focal lens options. There are also multi-focal contact lenses available to correct presbyopia.

Astigmatism

Astigmatism is a very common focusing error of the eyes which can cause blurred vision at both distance and near. It occurs as a result of irregular curvature on the surface of the cornea or on the lens of the eye itself. You can be born with astigmatism or it may develop as you age.

 Astigmatism can also occur in combination with either myopia or hyperopia.

People with astigmatism often experience tired eyes and may experience increased sensitivity to glare. They are often found to ‘squint’ in order to try and improve their vision.

Both glasses and contact lenses can correct for astigmatism.

Glaucoma

Glaucoma is often referred to as the silent thief of sight and is one of the leading causes of blindness.  Approximately 2% of people over the age of 40 have Glaucoma with the risk increasing with age. Glaucoma is an eye disorder resulting from damage to the optic nerve. This often occurs due to an increase in the internal eye pressure- but not always. Several tests may be required to diagnose glaucoma and early detection is important. Glaucoma cannot be prevented, but if diagnosed and treated early, it can be controlled. Vision already lost to Glaucoma cannot be restored.

For more information, visit www.glaucoma.org.nz

Cataracts

A cataract is a clouding of the normally clear lens within your eye resulting in blurred or distorted vision. Cataracts are most often found in persons over age 55.

Although cataracts develop without pain or discomfort, indications of cataract development may include blurred or hazy vision, increased sensitivity to glare or the feeling of having a film over the eyes.

If the cataract develops to the point that it affects your daily life and spectacles and contact lenses no longer help, you will be referred to an eye surgeon who may recommend surgery to remove the natural lens and replace this with a new plastic lens.

Hypertension (High Blood Pressure)

Signs of high blood pressure often appear first in the eye. Indicators can include narrowing of the blood vessels, spots on the retina, or bleeding in the back of the eye.

Retinal Detachment 

Retinas can lift or pull away from the wall of the eye. If not properly treated, this can cause permanent vision loss. Signs and symptoms include sudden onset of floaters or spots in your vision, white flashes or a shadow or curtain affect obscuring your field of vision. If you experience any of these symptoms, contact your Optometrist or an eyecare professional immediately.

Cancer

A dark spot at the back of the eye may signal a melanoma, which can grow unnoticed within the retina. If caught early, melanomas can be treated before they cause serious damage and travel to other areas of the body through the bloodstream.

Macular Degeneration

The macular is a small-specialised central area of the retina, responsible for fine detail and colour vision. Macular Degeneration is usually a slowly progressing disease where the central area becomes thin and damaged, resulting in reduced function.

A more severe form of Macular Degeneration exists but this is less common. In this condition blood vessels growing under the macula leak fluid or blood, which disrupts the smooth, even surface of the retina and damage the retinal cells. Vision becomes distorted and eventually reduces considerably. Early detection is important, as some forms of Macular Degeneration respond to treatment; however, lost vision is often not restored.

For more information visit www.mdnz.org.nz