Presbyopia is an age-related medical condition whereby a person loses the ability to see objects at near distance clearly. Everyone will develop presbyopia at some point in their lives. Even if one had perfect vision one’s entire life – one will begin to start having troubles with focusing at near distance, especially when performing tasks such as reading or threading a needle. This difficulty typically becomes evident around the fifth decade of life. However, it is the result of a gradual and progressive decline in the accommodative properties of the eye.
Presbyopia. Image Credit: Aijiro / Shutterstock
The lens is typically flexible and soft during our youth, but aging causes it to become increasingly more rigid and it loses its youthful ability to readily accommodate. This process occurs due to the continual growth of lens fibers throughout our lives, which is accompanied by a decrease in the length of the ciliary muscle and a directly proportional decrease in the strength of the muscle. The ciliary muscle, according to the Helmholtz theory, is a pivotal muscle in the accommodation process.
Age is the most important risk factor for developing presbyopia. It may, however, have an earlier onset in persons who have other medical conditions like hyperopia, or those who are on medications, such as antidepressant and antihistamines.
Presbyopia: Signs and Symptoms
Clinical Presentation
Affected people tend to notice that they find themselves having to hold their books, newspapers, smartphones, tablets or other objects that require near vision, further away from their eyes than usual. They mention having to do this in order to see what they are reading or doing clearly. However, as the object is moved further away from the eye, the smaller in size it becomes. This fact renders the maneuver only partially successful in dealing with presbyopia. It is also of purely temporary use, because accommodation further declines to a point where ophthalmological intervention becomes necessary.
Associated Signs and Symptoms
As with other ophthalmological conditions, people with presbyopia are at risk for experiencing headaches due to the constant strain placed on their eyes. Some people even avoid engaging in too many near vision tasks, where possible, due to the visual fatigue that they experience. The earliest signs and symptoms of presbyopia are blurred vision when attempting to do a task at normal reading distance. This, when combined with headaches and the tendency to hold near distance objects further away from the eyes than usual, is highly suggestive of presbyopia.
Symptoms are particularly worse when the individual is in an environment that is dimly lit. Other factors that may exacerbate the condition include being tired after a long day or having had too much alcohol. Presbyopia will have to be treated eventually, because, as mentioned earlier, there is further decline in the accommodative properties of the eye. People with presbyopia are advised to seek urgent medical attention if at any point there is sudden blindness in one eye or if they experience any phenomena, such as sudden hazy vision or black spots, flashes of light or halos around sources of light.
References
Further Reading