Maintaining good eyesight throughout your life is a vital part of ageing well and is a significant factor in retaining your independence and quality of life as you age. According to the Australian Bureau of Statistics, more than 13 million Australians have one or more long-term eye condition (data from the National Health Survey). The good news is that the World Health Organization and the Australian government estimate that between 80 and 90 per cent of vision impairment can be avoided through prevention or treatment. A good way to understand what damages your eyes is to look at the problems that commonly occur with eyes as people age.
Eyes under strain
Not all eye-related problems trace back to your diet, but some certainly do. Ultimately, your eyes are highly metabolically active and are exposed to light as their primary function, so a lot of the problems that arise with eyes are a result of oxidation. Here are some common eye problems that can develop with ageing.
Macular degeneration: Age-related macular degeneration (ARMD) is a major cause of blindness in older people. In both Australia and New Zealand, it affects one in seven people over the age of 50 and the incidence increases with age. The macula is a small area in the centre of the retina that is responsible for sharp, detailed central vision. The retinal pigment epithelium (RPE) is a layer of cells underneath the retina that passes oxygen, sugar and other essential nutrients up to the retina and moves waste down to the choroid. Macular degeneration occurs when this process breaks down and waste products from the retina build up underneath the RPE. As well as avoiding harmful habits such as smoking, eating foods rich in the antioxidant nutrients lutein and zeaxanthin can help prevent ARMD developing.
Cataracts: A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to ageing and can occur in either or both of your vision. The eye lens is constantly subjected to oxidative stress from UV light and other sources. Accumulation of oxidised lens components and decreased efficiency of repair mechanisms can contribute to the development of cataracts. Again, antioxidants such as vitamin C and the carotenoids lutein and zeaxanthin have been found to be associated with a decreased risk of cataract formation particularly in individuals exposed to high oxidative stress, such as heavy smokers, and those with poor nutrition.
Night blindness: Night blindness (nyctalopia) is the inability to see well at night or in poor light. Night blindness is a symptom of an underlying disorder or problem, particularly untreated myopia. Other causes include glaucoma medications, cataracts, retinitis pigmentosa and vitamin A deficiency. Treatment for night blindness depends on its cause. You may require a new eye prescription if you have untreated myopia or, if the night blindness is caused by cataracts, you may need surgery.
Retinitis pigmentosa: Retinitis pigmentosa (RP) is a condition that usually begins in the teenage years and slowly progresses during adulthood, resulting in either partial vision loss or blindness. Essentially, the retinal cells (rods and/or cones) are damaged causing vision to fade. According to some estimates, about one in every 3000 people is affected by RP.
Glaucoma: Glaucoma is the name given to several types of conditions that damage the optic nerve at the back of the eye. This damage occurs over time from excessively high pressure in the eye. The front part of your eye is filled with a clear fluid called the vitreous humour. This fluid is continuously made in the back of the eye. The fluid leaves your eye through channels in the front of the eye in an area called the anterior chamber angle. Anything that slows or blocks the flow of this fluid out of the eye will cause pressure to build up in your eye. In most cases of glaucoma, this pressure is high and causes damage to the optic nerve. If left untreated, this increased pressure can lead to progressive, permanent vision loss.
Glaucoma is extremely prevalent, with 10 per cent of people over the age of 80 in Australia and New Zealand being affected. A person with diabetes has twice as much chance of getting glaucoma as other adults. If you have a family history of glaucoma, then you are 10 times more likely to get the disease.
Diabetic retinopathy: Diabetic retinopathy occurs because diabetes can cause the blood vessels in the back of your eye to swell and bleed. This bleeding can slowly damage your retina and the longer you have diabetes, the more likely it is that you will develop diabetic retinopathy. Chances of diabetic retinopathy increase if your blood sugar is not well controlled, if you have high blood pressure, or if your cholesterol levels are high.
Nutrients for sore eyes
Your vision are highly susceptible to free radical damage because they depend for their very function on light and the reactions that flow from light entering the eye generate free radicals. Although all antioxidants will help to some degree, it is interesting that studies show that some antioxidants have a “preference” for some body tissues over others. It seems that lutein and zeaxanthin are especially beneficial to help your eyes recover from the damage caused to the retina by blue wavelengths of light. Other antioxidants such as vitamin A and vitamin C have special roles too.
Lutein and zeaxanthin: The antioxidant carotenoids lutein and zeaxanthin are widely distributed in a number of body tissues, but they are uniquely concentrated in the lens and retina. Lutein and zeaxanthin have both been shown to play a role in the prevention and treatment of certain eye diseases such as age-related macular degeneration and cataract. The biological mechanism for their protective effects is thought to be due to their powerful blue light-filtering activities and antioxidant properties. Healthy retinas have built-in mechanisms to protect against UV blue light damage, however blue light waves may be damaging to those who are prone to macular problems.
Research published in the Archives of Ophthalmology showed tha