Most changes in vision occur in the early and later years of life. Although some people may discover they have nearsightedness -- or difficulty seeing at a distance -- as late as their mid-20s, vision typically stabilize during the late teen years. From then until around age 40, vision typically changes little, if at all.
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Presbyopia - Age-related loss of close-up vision
At about 40 years of age, seeing to read or do close work such as sewing may become difficult. This is known as presbyopia. Presbyopia occurs because the crystalline lens in your eye loses flexibility as it grows thicker with age. This lack of flexibility affects the ability to focus on close objects.

Generally, by around age 45, reading glasses may be required for nearby tasks. If near- or farsightedness is also present, a number of vision correction options will be evaluated to best meet your needs.

Spots and floaters
People of every age may at times see spots and floaters, which appear to look like specks of material, cobwebs, thread-like strands or showers of brilliant crystals. During the middle years of life, they may become more frequent. These are optical defects that occur, as the vitreous, the jelly-like body in the main globe of the eye, becomes less jelly-like and more liquid as time goes by. This change is not always uniform, and so the mixture of jelly-like and liquid materials can affect the passage of light to the retina.

The result is seen as 'floaters.' Although spots and floaters are typically not of concern, they should be evaluated promptly. If you suddenly experience a large number of floaters, don't delay in making an appointment. A sudden change may signify that something is wrong.

Glaucoma
For adults, it is important to schedule regular eye examinations in order to detect and treat any occurrence of glaucoma in its earliest stages. Most types of glaucoma occur without the presence of any symptoms and can only be detected during a routine eye examination. Glaucoma occurs when fluid pressure inside the eye rises, cutting off the blood supply in the very small arteries carrying food and oxygen to the retina and causing loss of side vision or blindness if left untreated. It is a condition that can be arrested or slowed down but not reversed, so early detection is essential. Treatment often involves special eye drops or medicine, but, in some cases, surgery may be required. If detected early, chances that vision can be maintained are usually very good.

Retinal Disorders
Retinal disorders have a greater chance of developing in older adults, due to the aging process. Degeneration of the part of the retina called the macula causes loss of your central vision. Although the macula is no larger than a pinhead, the macula contains the visual cells needed for sharp vision and for seeing straight ahead. If these cells are damaged, it becomes difficult to see fine detail and read small print. People with macular degeneration are typically in good health. The condition does not appear to be caused by arteriosclerosis, high blood pressure or diabetes, by drinking alcoholic beverages, or by smoking. It is not caused by using your eyes too much. So far there are no medications for treating macular degeneration. Dietary supplements and vitamins have been suggested as a way to slow the degeneration.

Suggestions for better sight
Be aware of your visual limitations and compensate for them.
You may need more light for reading and other close tasks. Move the lamp closer to you and/or use a larger watt bulb. It is a fact that a 60 year old needs three times as much light as a 20 year old to see near work as easily.
Side vision and reaction time may reduce with age. Keep this in mind while driving or walking near traffic.
Limit night driving to well-lighted roads; keep headlights and windshields clean; and be visually aware of traffic.
Be sure to keep glasses clean.
Be sure to wear distance spectacles if they are prescribed for you. While you may feel that your distance vision is as good as it was when you were younger, very often this is not the case.
Although natural vision changes can't be prevented, they need not mean giving up activities such as driving your car. By practicing good health habits and having regular eye examinations, you should be able to continue an active, productive and independent life.