Common Eye Conditions

Nearsightedness / Myopia

Myopia is a vision condition and not an eye disease. It causes a person to have difficulty seeing clearly at a distance. Near objects are seen clearly, but distant objects do not come into proper focus.

The cause of this is due to light rays that enter the eye are bent too much and focus ahead of the back of the eye (the normal focusing point). Consequently the rays spread out prior to reaching the retina and so causing blurry vision.

Short sightedness is a common vision condition that normally occurs in school age children and affects about 30% of the population. As eyes continue to grow during childhood, Myopia usually occurs prior to the age of 20. An indication of short sightedness in a child is squinting at distant objects such as a television, cinema screen or black or a whiteboard at school.

Although corrective lenses may need to be prescribed, they may only have to be worn for certain activities dependent upon the severity of the condition.


Long Sightedness / Hypermetropia

As with Myopia, Hypermetropia is an eye condition. The condition causes rays of light to focus behind the back of the eye thereby causing blurring.

Unlike myopia individuals with this condition can focus their eyes to obtain clear vision at a distance (as you would focus a camera) and then have to focus with even greater effort to see clearly at close up distances.

The higher the degree of Hypermetropia the harder it is to focus. This usually results in eyestrain and/or headaches. Low degrees of Hypermetropia are usually unproblematic with higher degrees causing uncomfortable vision particularly with visually demanding tasks and sometimes even resulting in squints in young children.

Hypermetropia is common in children who may outgrow the condition as their eyes enlarge. Should this condition occur in unequal proportions to each eye and is not corrected; the result can be a permanent "lazy eye"(an eye which does not see as well as the fellow eye even with corrective lenses).

Signs of Hypermetropia include problems with concentration while attempting to focus on close objects, headaches after close up work, fatigue, eye strain, aching eyes, difficulty with reading, blurry vision and nervousness, irritability or tension after prolonged concentration.

Although in some cases the eyes may be able to compensate for this condition without the assistance of corrective lenses, more severe cases will require prescribed glasses or contacts lenses.


Astigmatism / Distorted Vision

The word Astigmatism seems to bring the dreaded fear of impending blindness to the minds of patients when advised their eyes are exhibiting this condition. However it is merely an eye condition just like myopia and Hypermetropia.

The simplest way to describe this condition is think of the astigmatic eye as more shaped like a rugby ball thereby having two different curvatures so allowing the rays of light entering the eye to focus at two different points. This condition may occur by itself or in conjunction with myopia and Hypermetropia.

Although many people have some degree of astigmatism, it is individuals with moderate to highly astigmatic eye conditions that may require corrective lenses. Severe cases of astigmatism will generally have blurred or distorted vision. More moderate cases may experience fatigue or headaches from eyestrain or blurry vision at some distances.

Spectacles or contact lenses (for even high astigmatism) are prescribed to correct this condition.

Uncorrected astigmatism in childhood can lead to a lazy eye so as with the other two conditions of the eye it is essential it is diagnosed early.


Presbyopia

Presbyopia is a condition of the eye where there is a lack of focussing for close work. It involves the crystalline lens inside your eye.

When the eye stops growing during the early teen years this lens continues to grow throughout life. Over time, the lens loses some of its elasticity resulting in the loss of some focusing ability. This decline of elasticity takes place over the course of a number of years, although it may appear to develop suddenly.

Presbyopia generally becomes evident to people in their early to mid-forties. This varies from individual to individual.

Early signs of this condition are those who have to hold reading material at arms length, have blurred vision at normal reading distance and experience eye fatigue along with headaches when attempting to do close work.

To correct this condition, spectacles or contact lenses have to be prescribed. Periodic changes in prescription lenses will be required to maintain optimum vision.


Squint / Strabismus

Strabismus is a condition where eyes are improperly aligned with each other causing double vision, as the eyes are not focusing on the same object.

Children under the age of six years are the group most affected. Strabismus may appear prior to 21 months. A child usually does not outgrow this condition and, if left untreated, the condition may worsen.

This condition may be noticed by a slight wandering of one or both of a child's eyes. The initial double vision, over time, may cause the brain to ignore the image from one eye. This can result in the development of Amblyopia.

If diagnosed and treated early, depending on the type of squint the misaligned eye may be straighten through the use of prescribed spectacles and in some cases surgery. The Amblyopia can be treated usually with effective results with patching treatment.

The condition rarely develops among adults. If it does then the adult usually experiences double vision which often difficult to join up into one image. A sudden onset of double should be investigated by a medical practioner. If in doubt then an eye examination will point you in the right direction.


Lazy eye/Amblyopia

A lazy eye or an amblyopic eye is one that does not see as well as it’s fellow eye even with a corrective lens. Depending on the individual The differences can be small or in rare cases so large that the weak eye can be considered to virtually blind.

It usually develops in children with uncorrected hypermetropia, myopia, or astigmatism particularly if there is a significant difference in degree of condition between the two eyes (known as anisometropia). It often occurs in those children with a squint. It can also develop in rare eye diseases or conditions such as a droopy eyelid and cataract (a cloudy lens in the eye)

With this condition the brain favours one eye over the other and over time, the ignored eye becomes weaker from lack of use.

Children who have a tendency to bump into objects on one particular side or display a noticeable favouring of one eye over the other should be examined.

Through a thorough eye examination, the presence of Amblyopia can be determined. The earlier Amblyopia is discovered, the greater the opportunity for a full recovery.

Amblyopia may be treated through prescribed spectacles or contact lenses and the patching of the good eye to allow the weaker eye to develop. This treatment is most effective as the child’s visual system is developing ie up to about the age of seven.