This is an excerpt from the book by Dr. Maneesh Kumar from Optometry Today India.
Errors of refraction
“Doctor, something has gone inside the right eye of Sonali”, the worried mother said as she entered the clinic, and continued, “and it also seems she sees less with her left eye”.
On preliminary examination, it was confirmed that the 6-year old Sonali’s left eye vision was weak. The foreign body, a piece of dust particle, which had settled on the black (in fact it is transparent, and gets its colour from the inside pigmentary structure, called iris) portion, the cornea, was removed by ophthalmic surgeon Dr. Maneesh Kumar, antibiotic eye drops were put, and Mrs. Banerjee was advised to come after three days for Sonali’s refraction test.
Immediately, it struck to me that some basic eye care issues need to be considered for the benefit of mothers like Mrs. Banerjee. Let’s deal with the problem of Sonali.
Nature has provided our eyes with eyelashes which are protective in nature. As soon as something strikes the eye, the eyelids close. But even then, sometimes, something does find a way to enter the eye and settle down. Inside the eye, the tears generally are in a position to flush out the foreign body. But if the foreign matter settles down on the sensitive structure cornea, it becomes painful, and the pain and discomfort will persist till remedial measures are taken. In such a condition, it is best not to touch or rub the affected eye.
Dr. Narendra Kumar
Editor, Optometry Today India
Dr. Maneesh Kumar is an ophthalmologist, and owns Ophthacare Eye Centre. He performs cataract, oculoplastic and other eye surgeries, and is also involved in minimising myopia progression by way of low concentration atropine therapy in selected cases.
Instead, keep it open, and gently rub the non-affected eye. It may seem unbelievable, but 9 out of 10 times the foreign matter will come out on its own. If, however, the stubborn thing doesn’t come out, then immediate professional help is a must, as otherwise, the situation might get complicated resulting even in a corneal ulcer.
When dust particle went inside Sonali’s right eye, she closed the eye, and then suddenly realised that she could not see clearly anymore. This made Mrs. Banerjee aware of the fact that Sonali’s left eye was weak.
Well, nature has provided us with a pair of eyes which move together when we look in front, in sides, and up or down. In order that we don’t suffer from eye-strain, headache or lack of depth perception, it’s imperative that the two eyes have normal vision, and the working of the external ocular muscles (which control movement of eyes), also is normal. In the absence of normal binocular vision, one eye tends to deviate outwards or inwards, resulting in a condition called squint.
Nature has provided us with eyes to look at all distances, far and near. But the modern living pace demands too much close work and neglect of out-door activities. This abnormal near-work demand on eyes results in a condition known as near-sightedness or myopia, wherein the affected person starts experiencing difficulty in seeing well at far.
Heredity is also an important factor in the development of myopia. Spectacles (with minus or concave lenses), contact lenses, and refractive surgery (i.e. LASIK) are the treatments available for this refractive error.
Since myopia, especially progressive myopia, is now assuming an epidemic form, however, eye care professionals have started taking specialized approach in the form of orthokeratology, or ortho-k contact lenses (worn at night and removed on awakening to provide adequate vision without correction), soft multifocal contact lenses (with peripheral myopic defocus in order to reduce eye’s axial length), and/or low-concentration atropine therapy (to discourage myopic progression). High myopes are at the risk of developing sight-threatening complications like macular involvement, retinal detachment, and glaucoma. And the best preventive measure is that everyone undergoes periodic professional eye examination as suggested in `Babloo goes for an eye test’ book (published by Optometry Today India, get yours from OptometryToday@gmail.com).
Sometimes, while a person sees well at far, there is difficulty in seeing well at near. The condition is known as hypermetropia (or Hyperopia), also called far-sightedness. Since a hyperopic eye is generally under strain, constant wearing of spectacles (with plus or convex lenses) is a must. Other treatment options are contact lenses and an excimer laser.
Another common refractive error is astigmatism, wherein nothing is seen clearly, and there may be a distortion of shapes of objects seen. This is due to the difference in the curvature of the two principal meridians of the cornea. Again, spectacles (with cylindrical lenses having power in one meridian only or a combination of sphero-cylindrical lenses as needed), contact lenses, or excimer laser can correct the anomaly.