Total Health Care – Vision

Vision changes

With aging, the quality of vision worsens due to reasons independent of aging eye diseases. The area of the pupil governs the amount of light that can reach the retina. The extent to which the pupil dilates also decreases with age. Because of the smaller pupil size, older eyes receive much less light at the retina. In comparison to younger people, it is as though older persons were wearing medium-density sunglasses in bright light and extremely dark glasses in dim light.

To maximize the light entering the eye, make sure that your eye glasses have anti-reflective coating. Anti-reflective lens coatings significantly reduce surface reflectance and allow greater light transmission through the lens. When AR coating is applied to both the front and back surfaces of a lens, the percentage of transmitted light increases to approximately 99% (compared to 90-92% with non-ARC lenses).

Aging causes a dramatic slowing in dark adaptation. Color vision changes cause some reduction of ability to discriminate blues and blue-greens. The yellowing of the lens is believed to be responsible for this effect. The aging lens and cornea causes glare by light scattering, especially for shorter wavelengths. Aberrations of cornea also increase with age, leading to poor vision especially when the pupil dilates as in the dark.

The most aggravating aspect of vision in an older person seems to be the feeling that it does not work as effortlessly or as quickly as it did in younger days. They must concentrate harder and require higher levels of illumination than they formerly did in order to have the same perceptual results.

Lighting the way

Everyone’s vision deteriorates with age, but there are ways to lessen its impact. Good lighting can make the difference between seeing and not seeing for older adults, especially in your homes, stairways, kitchen, living rooms etc. Naked bulbs: These are worst for older eyes, producing a glare that can be disorienting and painful. Task lighting: Light should be focused on the work, not toward the eyes. A good choice is a CFL with electronic ballast that starts up without flickering. Bathroom lighting: Lots of light should be provided overhead and even in the shower, where accidents are particularly common.

Anatomic changes

Aging causes laxity and downward shift of eyelid tissues and atrophy of the orbital fat. These changes contribute to the etiology of several eyelid disorders such as ectropion, entropion, dermatochalasis, and ptosis. The higher eyelid skin crease and ptosis may be due to age related disinsertion of the levator muscle aponeurosis, and to involutional atrophy of the orbital fat. The horizontal eyelid fissure shortens by about 10% with aging. With aging a prominent white ring develops in the periphery of the cornea- called arcus senilis. The corneal endothelial cells gradually decrease in number. The vitreous gel undergoes liquefaction and its opacities – visible as floaters gradually increase in number.

Aging Eye Diseases

Cataract: Cataract (‘safed motia’) is a clouding or opacity of the normally transparent lens inside the eye. It prevents the light rays passing onto the retina. The picture that the retina receives becomes dull and fuzzy. The normal process of aging causes the lens to harden and become cloudy (opaque). This is called age-related cataract and it is the most common type. It can occur anytime after the age of 45 years.

Glaucoma: Glaucoma (kala-motia, kala-paani) is a serious condition that involves an elevation in pressure inside the eye caused by a build-up of excess fluid. Left untreated, this pressure can impair vision by causing irreversible damage to the optic nerve and, eventually, blindness.

Macular Degeneration (ARMD): The macula is the part of the retina, which provides us with central vision and allows us to see fine detail, such as recognizing a face, reading, or watching television. Macular Degeneration is a condition in which the macula gets damaged. It is often related to aging, and is commonly referred to as Age-related Macular Degeneration (AMD).

Presbyopia: If you have presbyopia, you have the loss of the ability to focus up close that occurs as you age. Most people are between 40 and 50 years when they realize for the first time that they can’t read objects close to them.

Macular Hole: A macular hole is a small break in the macula, located in the center of the eye’s light-sensitive tissue called the retina. A macular hole can cause blurred and distorted central vision. Macular holes are related to aging and usually occur in people over age 60. It is 4 times more common in females.

Diabetic Eye Disease: Retinopathy is usually due to damage to vessels in retina. Retinopathy is usually caused by Diabetes (DM), but is sometimes caused by other diseases such as high BP.

Dry Eye: The most common cause of dry eye is a failure of the glands in your eyelids to produce tears, which often occurs as part of the ageing process.

The real problem of blindness is not the loss of eyesight. The real problem is the misunderstanding and lack of information that exist. If a blind person has proper training and opportunity, blindness can be reduced to a physical nuisance.

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