What is it?
Refractive Error is the condition of the eye when it cannot focus on an image clearly causing blurred vision and discomfort. It is a common eye condition that affects most of the population ranging from young children to older adults.
Types of Refractive Errors
- Myopia (minus power): also known as nearsightedness, is a condition where far away objects are not clear but nearby objects can be seen clearly. Due to the elongated shape of the eyeball, the image is formed in front of the retina causing far away objects to seem blurred. Myopia may increase up to the ages of 18 to 21. The symptoms include difficulty in seeing distant objects, like reading the blackboard in school.
- Hyperopia (plus power): also known as farsightedness, is caused when light rays focus behind the retina because of a shorter eyeball. Patients who are affected by this condition have difficulty in seeing nearby objects but objects far away remain clear. The signs and symptoms usually noted are difficulty in reading, headaches, eyestrain, and fatigue.
- High Myopia: is a condition of the eye where the power is negative 6 or more. It may increase even after 21 years of age and in some cases, the increase in power is severe that is termed as pathological myopia. Those affected by this condition may have further disorders such as retinal holes or detachment. Other symptoms include floaters or shady spots in the eyes, eye strain, etc.
- Presbyopia (plus power): is the normal phenomenon of ageing where the eye loses its flexibility to focus the light rays properly causing difficulty in seeing nearby objects. The symptoms include difficulty in reading, inability to thread a needle, holding newspapers at a distance, eye strain or headaches after reading.
- Astigmatism (cylindrical power): is a condition of the eye where the cornea has an irregular shape that prevents the light rays to focus at one point on the retina. This causes blurred vision and in some cases, it is associated with short or long sight. Wearing eyeglasses or contact lenses can correct this condition but in cases where astigmatism is very high surgical methods, such as, astigmatic keratotomy or LASIK is performed.
Some of the treatment options that are employed by doctors to treat Refractive Errors are:
- Eye Glasses are the most common solution to refractive errors because of the low cost and easy maintenance. Disadvantages of wearing eyeglasses may affect the appearance of a person and might interfere with activities such as playing sports, swimming, etc. It is also known to decrease peripheral vision.
- Contact lenses are an alternative to eyeglasses. These do not affect the appearance of a person and provides great peripheral vision. Disadvantage includes the cost of the contact lenses and their high maintenance.
Permanent Treatment Options
- Lasik (Laser in Situ Keratomileusis) uses a laser beam to reshape the cornea resulting in corrected vision as corneal curvature affects the power of the eye.
- Wavefront Lasik optical imperfections along with the curvature of the cornea are corrected with the help of a computer-guided laser technology, resulting in better and enhanced vision.
The eligibility criteria required for performing Refractive Surgery is as follows:
- The person should be above the age of 18 – 21 along with a stable eye power for over a year.
- No other eye disorders such as cataracts, glaucoma, etc. should be present.