Age-related changes occur throughout the body, including vision. More than 50% of all individuals with severe vision impairments are over the age of 65.
In addition, a study by Lighthouse International showed that 1 in 6 people over the age of 45 report some type of visual impairment, with more than half describing the impairment as severe. Changes with age occur in both the external and internal portions of the eye. Biannual eye examinations for those over the age of 40 will uncover an eye disorder at its earliest and most treatable stage. Some of the most common changes to the eye and its vision capabilities include the following.
The globe, also called the orbit, may seem to have sunken into the skull. This is the result of a breakdown or natural degeneration of the retrobulbar fat that supports the globe in the bony socket. Fortunately, the orbit is not susceptible to osteoporosis, as are other bones in the body. The orbit does not weaken or become thin and brittle with ageing.
Entropion is a turning inward of the eyelid and Ectropion is a turning outward of the eyelid. Both are common complaints associated with ageing, and both can be successfully treated with surgery if they produce discomfort or a threat to vision.
The conjunctiva (white portion of the eye) becomes slack and more susceptible to chronic inflammations with age. As it slackens, a section may become caught between the lids during blinking. Harmless degenerative plaques may appear on the conjunctiva. Tear glands and the conjunctiva may lose the ability to lubricate the eye, and artificial tears may have to be used.
Arcus senilis may appear on the margin of the cornea. This harmless white circle bordering the cornea is a common occurrence in the elderly. Composed of cholesterol and its derivatives, its presence does not necessarily indicate an overall raised cholesterol level.
Most aging eyes become presbyopic, a condition in which the hardened lens is unable to bend and focus effectively on objects at close range. Presbyopia usually surfaces near age 45 and affects both nearsighted and farsighted eyes. The condition is treated with reading glasses or bifocals.
The lens becomes opacified with age. Degrees of opacification vary and are not termed cataract until a significant opacification develops. The lens may yellow and cause color vision changes and nearsightedness.
The pupils lose their ability to accommodate quickly with changing light. They become smaller and reduces the light entering the eye to approximately thirty per cent of normal levels.
The vitreous may contain opacities that become visible to the individual as floaters, or spots that bounce or float in the field of vision. The vitreous may shrink, collapse, or detach from the retina, causing a more serious condition and vision loss.
The arteries and veins of the retina become narrower with age, reducing the flow of blood. The aging retina is duller and exhibits a less responsive light reflex. The optic disk may be paler also. This creates a need for more light in order to read or accomplish other tasks.
The eyelids may lose elasticity and tone, causing pitosis (drooping eyelids). This may cause a reduction in the area of visual field.
Visual acuity, or the ability to see small objects under normal lighting and contrast conditions, may suffer with age. The reduction may occur as a result of the smaller pupil and/or the aging, opacified lens. Decreased visual acuity may affect the ability to perform such tasks as reading or driving.
More light is required by the aging eye than a younger one. It is estimated that for every thirteen years of life, twice the amount of light is needed to function effectively. This may be the result of the smaller pupil and less transparent lens.
Contrast sensitivity and spatial perception reduce with age. The ability to detect and recognize contrast is controlled by the neural circuitry of the retina and brain. As neuronal changes occur, contrast sensitivity decreases. Spatial perception depends on contrast detection, so any reduction in contrast perception affects this ability as well.
Adaptation, the ability to be sensitive to changing light levels and adjust to them, is diminished with age. An elderly eye may require more time to recover from glare or a bright light as a flashbulb or car headlights. This is a result of the smaller, less adaptive pupil and the opacified lens.
Color vision may fade or change with age. The yellowing lens tends to absorb and scatter blue light, rendering blues darker and less intense. The unimpeded red and yellow light are allowed to pass through and cast a warm, reddish glow onto objects.
Vision loss occurs as a result of diseases that are associated with aging. The four leading causes of vision loss among the elderly are age-related maculopathy, cataracts, glaucoma, and diabetic retinopathy.
- Age-related maculopathy (ARM) is a progressive disease in which the macula, or area of sharpest central sight, deteriorates. Central vision and contrast enhancement is lost, but peripheral vision often remains intact. Some types of macular disease may be treated with laser therapy; and other advances in the treatment of ARM are occurring rapidly.
- Cataracts are opacifications or cloudy spots on the lens of the eye. Senile cataracts, those associated with ageing, are usually progressive and may exist for several years before requiring surgical removal. Cataract entails removing the lens and replacing them with artificial intraocular lenses or by a contact lens or glasses. The results of cataract removal vary from person to person, but are generally successful.
- Glaucoma is an increase in the intraocular pressure. This occurs when the eye produces an overabundance of aqueous fluid or when the eye fails to drain fluid adequately. The increase in pressure may damage organs of the eye and result in vision loss. Glaucoma can be treated and controlled with medications and surgery.
- Diabetic retinopathy is an eye disease that results from diabetes. The small blood vessels that support and nourish the retina become damaged and weak. These may hemorrhage and cause an accumulation of fluid in the retina that limits or alters vision. New, weaker vessels may proliferate, hemorrhage, and form vision-limiting scar tissue. This scar tissue may trigger a retinal detachment, and may result permanent vision loss.
Aging eyes may benefit from changes in the environment and lifestyle of the individual. Increased lighting and colour contrast, coupled with reduced glare may aid residual vision, increase effectiveness in the performance of tasks, and enhance safety. Adaptive aids may improve or enhance remaining vision, aid in the performance of skills and tasks, and increase independence.
All these conditions are improved or prevented by consuming more anti-oxidants and other nutrients.