Have you ever given a thought to how difficult (if not impossible) it would be – to identify and differentiate between colours; tell what time it is; watch your kids grow from infancy through adulthood; shed tears of toil or joy; capture the alluring sceneries of nature; give yourself that perfect ‘make-up mirror-look’ – without the eyes? What other machinery knows or does it better than them – in spilling emotions or spewing thoughts without words; in piercing hearts or procuring spoils without swords? How else could we have conceived, contemplated and communicated the idea of beauty, ugliness and everything in-between without these sublime and solemn creatures of perfection? What would we ever do without the polka-dotted, pristine duo that keeps staring at us from the mirror?
Today – Thursday, October 10, 2019 – marks the World Sight Day (WSD); an event which intercepts very well with the VISION 2020 mandate of eradicating preventable vision impairments by 2020. The major objectives of WSD include, raising awareness on blindness and vision impairment and securing funds and useful partnerships towards eradicating avoidable blindness and vision-related disorders. Although, it was originally an initiative of the Lions Club International Foundation in the year 2000, WSD has grown to become a globally recognised event. The International Agency for the Prevention of Blindness (IAPB) is currently saddled with the responsibility of organising the WSD event yearly (on the second Thursday of October), in conjunction with the World Health Organisation (WHO). The theme for this year’s event is ‘VISION FIRST’; some themes from previous years include – EYE CARE EVERYWHERE (2018); MAKE VISION COUNT (2017) and STRONGER TOGETHER (2016). According to IAPB, of the 253 million visually-impaired persons worldwide, about 217 million suffer from moderate or severe distance vision impairments (MSVI), whereas the other 36 million are blind. A majority of these visual impairments (up to 75%) are avoidable or treatable, but the victims are barely aware of any effective precautions or solutions.

The eye is the organ for sight; it functions in concert with the brain to perceive light, colours, images, and to interpret them. Owing to its delicate and fragile nature, the eye enjoys significant protection from its lashes, lids and the bacteriocidal tears it secretes via the lachrymal gland. The major components of the human eye are its pupil, iris, cornea, lens, ciliary muscles, retina, blood vessels and optic nerve (which serves as a link between the eyes and the brain).

The retina, the light-sensitive region of the eye (which plays a major role in focusing images captured by the lens – more or less like a camera film does), consists of two (2) major types of photoreceptor cells implicated in visual transduction (the complex, sequential, highly coordinated process that vision entails). Photoreceptors are the microscopic structures responsible for receiving and transmitting the light that falls on the retina. The ROD-shaped ‘light-sensing’ photoreceptor cells are responsible for detecting shape and general, ‘black-and-white’ vision; while the CONE-shaped ‘colour-sensing’ photoreceptor cells help us identify details and differentiate between colours. There are about 120 million rod cells, and 6 million cone cells distributed over the surface of the retina in the human eye. A third photoreceptor plays roles that are not directly associated with vision.
Vision is achieved – via the visual transduction cascade – in few milli-seconds (>0.001s). This cascade runs from light falling on the retina and focusing an image, and ends with an accompanying interpretation from the brain (via the optic nerve).

Some eye defects and vision impairments are; cataract (lens-cloudiness), myopia (short-sightedness), hypermetropia (long-sightedness), astigmatism (uneven curvature of the eye or lens), glaucoma (deterioration of the optic nerve), colour blindness (an inability to differentiate clearly between colours), strabismus (a lack of pupillary coordination), night blindness (a deficiency in vitamin A – the precursor to RETINAL, a major component of the photoreceptor pigment, RHODOPSIN), presbyopia (hardening of the lens and loss of focus, often associated with old age) and the often age-related macular degeneration. Treatment and management options for these defects range from improved diets and nutrient supplements, to drug and lens prescriptions, surgery, and the more recent CRISPR gene-editing therapy (that replaces a missing or mutated gene implicated in vision).

Here are a few tips on Eye Care;
| Eat a balanced diet (and get enough vitamin A – from palm oil, dark green, leafy vegetables, carrots, cod liver oil, dietary supplements and fortified foods);
| Exercise regularly, keep a healthy weight;
| Take regular eye check examinations, (often with an optometrist);
| Cut-down on alcohol, avoid smoking;
| Use sun-shades and eye-protective devices;
| Read with bright lights;
| Know your family health history;
| Identify and manage risk factors eg. diabetes;
| Use only prescribed lenses, abstain from all forms of self-medication;
| Rest.

Although, the realisation of the VISION 2020 goal still appears to be a very far-away possibility, it is not at least unrealistic, neither is it unattainable. If we all played our part, the year 2020 would definitely be our long-awaited year of ‘One Sight & Zero Visual Impairments’ – Let’s make it work!

Learn a new Word
CATARACT: Cataract is a vision impairment characterised by a cloudiness of the normally clear lens of the eye. This cloudiness is called ‘cataract’. It is one of the most common causes of blindness, especially in adults. Cataract may result from a variety of factors that include, aging, diabetes, birth defect and eye injury. Common symptoms of cataract include; blurred or dim vision, poor night visibility, inability to read properly, yellowing or fading of colours and double vision. A safe, often effective surgery can correct the visual impairments caused by cataract in an individual; especially when improved lighting and glasses have proven ineffective in managing the condition. Although, it is not yet clear whether any activity or food could help prevent cataract, adopting a healthy lifestyle and dietary regimen – exercising, avoiding smoking, reducing alcohol intake, consuming lots of fruits and vegetables, cutting down on junk foods, amongst others – in addition to a regular eye examination could help reduce one’s risk of contracting cataract.

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