Myopia Hyperopia and Astigmatism
Myopia, Hyperopia and Astigmatism
“I am not out of shape, oval is also a shape!” argued Eyeball M. Eyeball H’s guffaw was cut short by the rude Eyeball A, “What are you laughing at, you midget?”…and so the three broke into a scuffle. While these three battle it out, let us have a look at who they are:
Meet Eyeball M: Also called Mr Myopia, he’s elongated like a rugby ball and squints when he tries to see distant objects.
Myopia or near-sightedness is a common vision problem in which you can see objects near you very clearly, but faraway objects seem blurry. It may be mild where you can see objects clearly even if they are several yards away, or it may be severe where you can see objects clearly only if they are just a few inches away. It is often first detected during childhood.
In a normal eye, the cornea (the transparent front surface of the eye) is evenly smooth and it bends (refracts) incoming light so that a sharply focused image is formed on the retina (a screen at the back of the eye).
In myopia, the eye is longer than normal or the cornea is curved more outwards and hence the incoming light is focussed in front of the retina instead of on the retina, causing a blurry image.
a. It tends to run in families.
b. People doing a lot of reading or close work may be at a higher risk.
• Blurry vision when looking at faraway objects.
• Having to squint or partially close your eyes when seeing at a distance.
• Headaches after eyestrain
• Difficulty in seeing while driving at night.
• Blinking excessively.
• Rubbing eyes constantly.
• Requiring to sit very close to the TV or blackboard in the classroom.
• Holding books too close while reading.
• Seeming unaware of distant objects.
Reduced quality of life
Safety Impairment of yourself and those of others if you drive or operate heavy machinery with uncorrected vision.
Increased chances of developing Glaucoma (a disease where there is raised pressure inside the eye).
Retinal tear and Detachment: In severe myopics, the retina is very thin and at risk of tearing or detaching.
1. Corrective Lenses:
They counteract the increased corneal curvature or eye length. These could be either glasses or lenses like soft/hard/disposable/extended wear/rigid gas permeable.
2. Refractive Surgery:
LASIK (Laser-assisted in-situ keratomileusis).
LASEK (Laser-assisted subepithelial keratomileusis)
PRK (Photorefractive keratectomy)
IOL (Intra-ocular Lens) Implant
A basic eye test is sufficient.
Introducing Eyeball H or Ms. Hyperopia, who is short and has to strain to see nearby objects.
Hyperopia, better known as far-sightedness is a vision problem in which distant vision is clear, but nearby objects appear blurred.
Far-sightedness usually is present right from birth, but children have a flexible eye lens which compensates for the problem. Most children outgrow this condition.
In Hyperopia, your eyeball is shorter from front to back or your cornea is curved too little. Hence the incoming light is focussed at a point behind the retina, instead of on the retina, causing blurring of the image. This condition also runs in families.
• Pain in eyes
• Headache while reading
• Blurry vision for nearby objects
• Crossed eyes in children
A general eye examination which includes:
• Refraction test
• Eye movement testing
• Retinal examination
• Glaucoma testing
• Visual acuity
• Slit lamp examination
Lazy eye (A condition in which one of your child’s eye has poorer vision than the other)
Reduced quality of life.
• Eye glasses and Contact lenses.
• Refractive Surgeries like LASIK, LASEK, PRK and Conductive Keratoplasty (CK).
Protect your eyes from the sun
Eat healthy foods
Use good lighting
• For those at high risk of certain eye diseases: every two to four years up to age 40, then every one to three years between 40 and 54, and finally every one to two years at age 55 and older.
• For those with no symptoms of eye problems: An initial exam at 40, every 2 to 4 years between ages 40 – 54, every 1 to 3 years between ages 55 – 64 and then every 1-2 years after age 65
And, the last of them all, Eyeball A. Mr. Astigmatism is different than any other of his kind.
Astigmatism is a mild, common easily treatable imperfection in your eye curvature. It is often present at birth and may be seen in combination with myopia and hyperopia.
Here, your cornea or lens is curved more steeply in one direction than the other. Hence images that you see will be blurred more in one direction. Eg. Horizontal images may be more out of focus than vertical or diagonal. Thus, instead of being smooth throughout, some surfaces may be flatter or steeper than the others.
The exact cause is however, unknown.
It may sometimes be seen after certain eye surgeries like cataract surgery, injuries or diseases.
Fine details cannot be seen either at a distance or close up.
It is detected by a standard eye exam along with a Keratometry and Corneal Topography.
Uncorrected astigmatism in a single eye can lead to amblyopia.
If mild, it need not be corrected.
Glasses or contact lenses can correct it.
Laser surgery can correct the distorted shape of the cornea.
Astigmatism, Myopia and Hyperopia are the three types of refractive errors where light rays are not refracted properly because of improper curvature of the lens or cornea or eyeball.
Do keep an eye out for these three brats: Mr. a, Ms. H and Mr. M!