COMMON VISUAL PROBLEMS
In a perfectly shaped eye, the cornea (which is the clear front surface of the eye) and the natural crystalline lens (a clear structure inside the eye that changes shape to help with focusing) help you to see sharp images. However if the cornea or lens are not correctly matched, light rays will not be bent properly and refractive errors will result.
The prevalence of myopia in Singapore is one of the highest in the world, affecting around 20% of children aged 7 years and 80% of boys by the time they enter national service.
Myopia (Short-sightedness or Near-sightedness)
Myopia, also known as shortsightedness is the most common refractive error in Singapore affecting around 80% of the population.
It is a refractive condition due to either the eye being too long or the cornea being too curved, resulting in the image focusing just in front of the retina. In this case, distant objects are not seen clearly.
Hyperopia (long-sightedness) is a refractive condition due to either the eye being too short or the cornea being too flat, resulting in the image focusing just behind the retina. Here, near objects are not seen clearly.
Astigmatism (“San Guang”)
“San Guang” or astigmatism occurs when the cornea is curved more steeply in one direction.
This causes the image to be distorted when it is focused on the retina. It can occur with either myopia or hyperopia and results in the blurring of both distant and near objects.
Presbyopia (“Lao Hua”)
Presbyopia (“lao hua”) takes place as the eye ages and loses the ability to focus on near objects (Accommodation). This is believed to be due to the loss of elasticity of the crystalline lens.
Presbyopia usually affects those above 40 years and symptoms include difficulty with near tasks such as reading and sewing.