The Aging Eye

As one ages, certain eye changes that are attributed to the aging process starts occurring. In old people, visual changes due to refractive error is one of the most frequent reasons for consultation with an eye care practitioner and
uncorrected refractive error is the most common cause of reduced vision. In addition,

other eye conditions like glaucoma and cataract are associated with aging.

As one ages, the eye might develop one or more of the following eye conditions.

Presbyopia; The crystalline lens is a structure inside the eyes that enables us to see clearly both at far and at near (especially at near). This lens is held in a vertical position at both ends by a muscle called the ciliary muscle. Contraction and relaxation of the ciliary muscle changes the shape of the lens which makes us see clearly. When the two ciliary muscles holding the lens contracts (when viewing far objects), the lens is stretched (becomes flat) but when these muscles relax (when viewing near objects), the lens assumes a domed shape.

As one ages, the ciliary muscles and the lens becomes overstretched (loses their elasticity). The lens becomes thick, hard and less flexible and is no longer in a domed shape. This makes the eyes difficult to see near objects clearly.

This condition is known as presbyopia and usually begins at the age of 38 to 45 years. It is corrected with special type of spectacle called reading add. Reading adds are prescribed by eye doctors.

Cataract; Cataract development is a gradual consequence of aging and significant cause of vision loss. The total number of adults with cataract is expected to increase to 30.1 million by year 2020.

During the aging process, the lens becomes thick, hard and white (nuclear sclerosis). This process is accelerated by the oxidative damages that occur in the lens which will eventually lead to cataract development. Antioxidants can be used to slow down these oxidative damages.

Glaucoma; Just as hypertension (high blood pressure) is mostly prevalent in old individuals, glaucoma is usually observed in old people. Unfortunately, approximately half of all patients with glaucoma do not know they have it and will likely suffer unnecessary vision loss. This is because glaucoma (90 percent of cases) usually comes without symptoms except when it becomes worst that the patient starts to notice reduction in his or her peripheral (sides) vision.

Age-related Macular Degeneration (ARMD); ARMD is the degeneration of the central point in the retina (macular) that is responsible for detailed vision. It is the leading cause of blindness in developed countries, occurring at the age of 59 years or older. The patient experiences distorted vision and central shadowing.

There are other conditions that affect the eyes due to aging and their consequences on the visual system includes; reduced visual acuity, reduced contrast sensitivity, reduced color discrimination, increased sensitivity to glare and increased time taken to adapt to sudden change in luminance.

Lighting can be used to compensate for these changes, to some extent and hence can be used to support the independence and quality of life to elderly. In addition, regular eye examination has proven helpful.