Can Eyes See Clearly?
05 April 2019
Vision plays a crucial role in our lives from infancy to adulthood as our eyes are known as our body’s most highly developed sensory organs. However, eyesight is something that most of us take for granted.
It is important to note that early detection of vision problems, especially during the childhood years, is essential to ensure one is equipped with the necessary visual skills to perform at the most optimum level. That is why parents should get a child’s eyes checked during his formative years and stay informed about the type of vision problems and correction options should a child needs it.
Even adults get eyesight problems. Vision correction is achievable in most cases. Here are the common vision problems and their description:
Age-related Macular Degeneration (AMD)
AMD is the leading cause of blindness in people aged above 60. It happens when the small central part of the retina, known as the macula, deteriorates. There are two main types of AMD: Wet and dry.
Wet AMD happens when there is growth of abnormal blood vessels under the macula. These blood vessels often leak blood and fluid. Loss of central vision usually happens quickly, hence wet AMD is also known as advanced AMD.
Dry AMD occurs when the light-sensitive cells in the macula start to thin or slowly break down, leading to tissue death. Patients with dry AMD may have blind or blurred spots in the centre of their vision. In advanced stages, patients lose central vision.
Astigmatism
Astigmatism is a common eye condition that can usually be corrected by eyeglasses, contact lens, or surgery. This condition is caused by an eye that is not completely round. Our eyes are normally shaped like a sphere. However, in astigmatism, the cornea in the eye has a non-round curvature – like the back of a teaspoon or an American football.
People with astigmatism may have a random, inconsistent vision pattern, wherein some objects appear clear and others blurry. Most regular astigmatism occurs with other vision problems such as nearsightedness or farsightedness, and is fully correctable with properly prescribed glasses or contact lens. Irregular astigmatism is far less common and is associated with abnormal eye conditions such as keratoconus. This condition is more effectively treated with rigid gas permeable contact lens or corneal transplant procedure.
Cataracts
A cataract is a clouding of the lens of the eye that can impair vision. Cataracts are the most common cause of vision loss in people over age 40. It happens when there is a buildup of protein in the lens. This prevents light from passing clearly through the lens, causing some loss of vision. Cataract vision may be worse in dim light.
If the vision loss cannot be corrected with glasses and the condition is affecting your daily life, cataract surgery is a viable option. The surgery involves removing the clouded lens and replacing it with a clear, artificial one. This procedure can successfully restore lost eyesight in most cases.
Colour Blindness
A person with colour blindness, or a colour vision problem, has trouble seeing red, green, or blue or a mix of these colours. The cause of this is usually due to genetic reasons, or can be a result of other diseases such as diabetes and multiple sclerosis.
Most of us have three types of cone cells in our eye. Each type senses red, green, or blue light. Inherited colour blindness happens when one type of these cone cells is missing or is not working properly.
There are different types of colour blindness and there are extremely rare cases where people are unable to see any colour at all. As colour blindness can have a big impact on one’s life, it is important to detect the problem as early as possible. With early screening and detection, you can find ways to help make up for a colour vision problem.
Diabetic Retinopathy
Diabetes is a chronic condition associated with abnormally high levels of glucose in the blood. This is a disease which can cause complications to our brain, heart, kidneys, feet and even eyes.
Retinopathy is a disease of the retina. For patients with diabetes, diabetic retinopathy can lead to poor vision and even blindness. This is due to bleeding from small blood vessels on the retina at the back of the eye. Diabetic patients can also get macula edema or swelling of the centre of the retina.
Diabetic retinopathy is treated with laser therapy applied to the peripheral retina. This helps shrink the bleeding blood vessels in the eye and stops further bleeding. Macula edema can be treated with gentle laser therapy and drug injections into the eye.
Most of the time, there are no symptoms of diabetic retinopathy until it starts to change your vision. This is why it is important for diabetic patients to get their eyes checked regularly. Good control of diabetes with medications, and good diet control can also help prevent these eye complications from recurring.
Farsightedness
Also called hyperopia, images are focused slightly behind the retina, making nearby objects appear blurry. Some children are born with this condition, but most outgrow it as the eyeball lengthens with normal growth. Sometimes, people confuse hyperopia with presbyopia, which also causes near vision problems but for different reasons. Farsightedness can be corrected with glasses or contact lens.
Floaters
Eye floaters are small moving objects like black spots, lines cobwebs, ring shapes that appear in your field of vision. The black compartment of our eye is filled with a transparent jelly called vitreous. As we age, this vitreous jelly will detach from the retina and the pieces of this jelly are what is seen as floaters. Benign eye floaters usually do not require treatment. Serious floaters can cause a retinal hole, which can lead to retinal detachment. Retinal holes can be treated with laser.
Glaucoma
Dubbed as the “silent thief of sight”, eyesight in some glaucoma patients is gradually lost and by the time they are aware of it, they may have lost almost 90 percent of their field of vision. Glaucoma is due to raised pressure inside the eyeball and usually occurs over the age of 40. The increased pressure can damage the optic nerve, which transmits images to the brain.
There are two types of glaucoma: Open angle and closed angle. Open angle glaucoma, the most common type, usually appears in middle age and seems to have a genetic component. This type causes gradual loss of vision and has no pain. It is usually treated with eye drops. Closed angle glaucoma comes on quickly, can cause eye pain and sudden loss of vision, hence requiring immediate medical attention.
Lazy Eye
Amblyopia, a medical term for lazy eye, means that vision in one eye does not develop fully during early childhood. Usually, amblyopia is a correctable problem if it is treated early. Late treatment can mean that the sight problem remains permanent. A squint is one of the most common causes of amblyopia. Treatment involves making the amblyopic eye work harder to see. This is usually done by blocking the vision in the good eye with a patch or making the eyesight in the good eye blurry by using atropine eye drops.
Nearsightedness
Opposite of farsightedness, nearsightedness, also known as myopia, is the result of images being focused in front of the retina rather than on it, so distance objects appear blurred; in other words, difficulty in seeing far. This is most common optical disorder and usually develops in childhood. This vision problem is usually corrected with prescription glasses or contact lenses.
Presbyopia
Presbyopia is when you feel a need to hold reading material at arm’s length. This happens because there is a loss in your eye’s ability to change its focus to see objects that are near. Presbyopia is part of the natural aging process of the eye, as with wrinkles, and the condition generally starts around age 40. Bifocals are usually prescribed for this condition.
Retinal Detachment
Retinal detachment is a very serious eye condition where the retina separates from the back of the eye. Permanent loss of vision can occur if this is not treated promptly. Retinal detachment happens in less than one in 10,000 people but is more common in people with myopia, who have had previous eye trauma, or complicated cataract surgery. Symptoms include flashes of light, floaters and darkening of your side vision. Treatment usually includes vitrectomy surgery, laser burns to seal the retinal holes, followed by insertion of a special gas or silicone oil into the eye to prevent the retina from redetaching. Modern vitrectomy surgery can now be done without sutures and under local anaesthesia.
Squint
Also known as strabismus, squint is a condition where one eye appears to drift inwards or outwards. Most squints occur in young children. Double vision from a squint is not noticed by a young child because the image from the affected eye is rapidly suppressed by the brain, which can lead to amblyopia (lazy eye).
A squint is usually due to a refractive error that can be corrected by wearing glasses and surgery to realign the eye muscles. Patching of the better eye to encourage the child to use the lazy eye is also done if amblyopia is present.
Reference:
- 1. Eye Problems and Diseases. Available at http://www.allaboutvision.com/conditions/
- 2. Recognize These Common Eye Conditions. Available at http://www.medicinenet.com/eye_diseases_pictures_slideshow/article.htm
- 3. Detecting Eye Diseases and Conditions. Available at http://www.webmd.com/eye-health/detecting-eye-diseases-conditions
