This form of eyesight deterioration – specifically near vision - comes naturally with age. It is caused by the loss of flexibility in the eye’s lens making it difficult to focus on objects that are near.
You may have presbyopia if you have: a tendency to hold reading material at arm’s length, blurred vision when holding reading material at a normal length, or eye fatigue and headaches when reading closely.
Nearsightedness is a result of the eye being longer than usual from front to back. This causes images to focus in front of the retina instead of directly on its surface. As a result, far objects appear blurry and are difficult to focus. Myopia is measured in negative dioptres.
This condition occurs when the eye is too short from front to back. As a result, images focus behind the retina instead of directly on its surface. When people are farsighted, close objects appear blurry and difficult to focus on. Hyperopia is measured in positive dioptres.
Astigmatism is caused by an irregularly shaped cornea, appearing more oblong (like a football), as opposed to a sphere (like a basketball). This causes images to focus at different distances and can cause double images or ghosting. Astigmatism is also measured in diopters, with a cylinder axis detailing the orientation of the blur.
Lasik laser assisted in situ keratomileusis is a type of refractive surgery for the correction of myopia, hyperopia, and astigmatism. LASIK is performed by an ophthalmologist, who creates a thin protective layer of corneal tissue using a precision laser (Intralase) or blade. This layer is called the "flap" and is gently folded back to reveal the inner cornea. A computer controlled excimer laser beam then specifically reshapes the cornea according to your prescription. The flap is repositioned and acts to cover and protect the area.
PRK (Photorefractive Keratectomy) is an alternative procedure to Lasik for those patients who have thin or irregular corneas. It can also correct for myopia, hyperopia and astigmatism. The surgeon removes the outer cells of the cornea and reshapes the inner corneal surface with a laser. No flap is created. A bandage contact lens is inserted in the eye to help with corneal healing. This means that although it takes longer to heal after surgery, there is more tissue spared in the eye.
Please visit the TLC Laser Eye Centre website for more information.
Amblyopia, or "lazy eye," is the inability of an eye to see clearly, even through glasses. It is the most common cause of vision problems in children and occurs when the nerve pathway from the eye to the brain does not develop properly during childhood. This confuses the brain, which may ignore the weaker eye. Strabismus (an eye turn) and a high prescription in one eye are the two leading causes of amblyopia.
To treat amblyopia in children you must first correct the cause of why the vision is poor in one eye. Glasses are often used to correct a prescription and eye exercises or surgery may be used to correct a turned eye. Next, a patch is placed on the normal eye. This forces the brain to use the weaker eye.
Children who get treated before age 5 will usually recover almost completely normal vision, although they may continue to have problems with depth perception. Early recognition and treatment of the problem in children is the best way to prevent permanent visual loss.
Glaucoma is an eye disease in which the optic nerve is damaged in a characteristic pattern. This can permanently damage vision and lead to blindness if left untreated. It is normally associated with increased fluid pressure in the eye and leads to a loss of peripheral vision.
Glaucoma can be roughly divided into two main categories, "open angle" and "closed angle" glaucoma. The angle refers to the area between the iris and cornea, through which fluid must drain. Closed angle glaucoma can appear suddenly and is often painful. Visual loss can progress rapidly, but patients often seek medical attention quickly before permanent damage occurs. Open angle, chronic glaucoma progress at a much slower rate and patients may not notice any vision decline until the disease is well advanced.
Glaucoma treatment usually involves the use of eye drops to lower the intraocular pressure. Occasionally surgery may be recommended to further aid fluid drainage. Automated visual field tests are done to diagnose and monitor any peripheral visual field loss.
A cataract is any type of clouding that develops in the crystalline lens of the eye. Depending on the severity of the clouding, patients will notice their vision looks hazy because there is an obstruction of the passage of light into the eye. Patients also complain that there is more glare and halo around lights, as the clouded lens can scatter light rays entering the eye.
Most cataracts develop as a normal age related change in the eye. However, injury, certain medications and eye surgery can also cause cataracts to form. Some children develop cataracts, called congenital cataracts, before or just after birth. These require intervention immediately to prevent the child from developing amblyopia.
Once a cataract has developed enough to be affecting vision, surgery can be performed to remove the hazy lens. A replacement lens implant, or IOL is inserted into the eye to help reduce a patient’s post-operative glasses prescription. Surgery is generally done until local anesthetic and takes about fifteen minutes.
Age-related macular degeneration (AMD) is a condition typically affecting older adults and results in a loss of vision in the center of the visual field because of damage to the macula. The macula is a small oval shaped area in the centre of the retina, which is responsible for all of our detailed central vision.
Macular degeneration occurs in both the “dry” and “wet” forms. In the dry form, cellular debris called drusen slowly accumulates between the retina and the underlying layer, and the retina can become locally detached. In the wet form, which is more severe, blood vessels grow up from the layer behind the retina, and the retina can also become detached. Both types result in poor central vision and can make it difficult or impossible to read or recognize faces.
Wet AMD can sometimes be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels.
The Age-Related Eye Disease Study (AREDS) found that supplementation with antioxidants plus zinc decreased the likelihood of developing advanced age-related macular degeneration in some people. Thus, most eye doctors strongly recommend an eye-specific antioxidant vitamin supplement containing the established dosages of A, C, E, zinc, selenium, copper and lutein and zeaxanthine (two pigments found in the macula). A diet rich in lutein and zeaxanthine (green leafy vegetables such as spinach, kale, and collard greens) and Omega 3 (salmon, sardines) is also recommended.
Diabetic retinopathy is damage to the retina caused by complications of diabetes, and if left untreated can eventually lead to blindness. There are often no early warning signs for diabetic retinopathy, although patients occasionally complain of blurry or fluctuating vision.
New blood vessels can grow at the back of the eye and can bleed and blur vision. Initially, theses blood spots may appear as floaters in the vision and clear after a few days. In more severe cases, the blood may take weeks or months to clear from inside the eye – or may not clear at all. Focal laser treatment may help in retaining or regaining lost vision.
The longer a person has diabetes, the higher his or her chances of developing diabetic retinopathy. This is why routine eye health examinations are so important for all Type 1 and Type 2 diabetics.