Really seeing what you're looking at

Optometry is a health care profession in which the optometrist measures the degree of eyesight. The optometrist's aim is to achieve the best possible method for having 6/6, single, clear, comfortable, binocular vision.
6/6 vision means you have normal vision and that you are able to distinguish details and shapes at 6 metres.
If necessary, the optometrist will prescribe correctional spectacle lenses, contact lenses or eye exercises for the associated visual defect. He/she should also be able to detect eye diseases and refer accordingly for further management or treatment.
What causes decreased vision?
There are two major categories, namely refraction problems or pathology.
Refraction problems cause decreased/blurred vision when light rays do not focus perfectly on the macula, while pathology refers to eye diseases or any deviation from normal ocular structures that interfere with processing normal vision. Refractive problems in the absence of pathology can be corrected with optical lenses. In the case of any pathology being present, vision might not be correctable to 6/6 and further medical/surgical intervention would be required, with or without optical lenses being prescribed.
Refraction problems include:
• Myopia or short-sightedness;
• hyperopia or far-sightedness;
• astigmatism, when light rays focus on two different points, due to the cornea or lens not being smooth enough;
• presbyopia, or the decreased ability of the eye’s crystalline lens to focus clearly on near objects.
Ocular pathology includes a very wide field. The eye itself is a small and delicate organ, with many structures and layers each playing an essential role in normal visual functioning. The slightest change in structure may cause a visual defect. Common ocular pathology includes:
• Pterygium – triangular, pink, fleshy growth on the white part of the eye;
• Keratoconus – thinning of the cornea into a cone shape;
• Cataract – opacification of the crystalline lens and it might best be described as looking through a dirty window;
• Glaucoma – damage to the optic nerve which will cause gradual visual loss;
• Age related macular degeneration; and
• Diabetic/hypertensive retinopathy – a retinal condition that might be found in diabetic and hypertensive patients, due to damage of blood vessels.
It is important to inform your optometrist about any previous ocular conditions or that are present in your immediate family. Also notify your optometrist about your medical condition and history as well as any chronic systemic medication that you are using.
Your eyes are part of the rest of your body, sharing the same circulatory system and are affected by how you maintain your health and diet.
Smoking also has a negative impact on your eyes, playing a role in cataract formation and macular degeneration.
The optometrist can use of the following methods to help correct vision:
• Spectacles/sunglasses;
• Soft contact lenses;
• Rigid gas permeable lenses (hard contact lenses);
• Scleral lenses (large diameter rigid gas permeable lenses which do not touch the cornea);
• Orthokeratology, which involves fitting a carefully designed rigid gas permeable lens to temporarily reshape the cornea overnight to correct refractive problems; and
• Low vision devices, including different types of magnifiers.
The optometrist may also refer you to an ophthalmologist to determine if you are a good candidate for refractive surgery such as alteration of corneal shape or insertion of an artificial lens. Other factors such as age and medical condition play an important role.
Finally, regular eye examinations are essential to maintain optimal visual functioning and ocular health.
Article supplied by the Namibian Optometric Association