When we were discussing conditions that result in poor vision or cause complete blindness, and that affect our perception of the surrounding environment, I was expecting a discussion on cataract as well. However, there was no mention of cataract, and I wanted to research on this condition. Cataract is a cloudiness that develops in the lens of the eye, and thereby, restricts light from entering the back of the eye and reaching the retina and impairs vision. If left untreated, cataracts will usually continue to develop until vision is completely obscured and the eye is blind. Though cataracts are more of a natural feature of aging, research shows that they can occur at any age and be accelerated or caused by ultraviolet radiation, steroids, severe diabetes, and as a result of inflammation within or injury to the eye.
Cataract can affect depth perception because it sometimes develops more quickly in one eye than the other. Because one eye can still see clearly, many people unconsciously rely on it and fail to notice the poor vision in the other. This reliance on one eye affects their depth perception, misjudging distances, which may be problematic when driving. In addition, cataract impairs a person’s ability to perceive colors, blues and purples in particular. Symptoms also include short-sightedness because as some cataract develop, they increase the power of the lens and its ability to bend (refract) light, and this increase in refracting power can make the eye more short-sighted. Among other symptoms, glare is also one. Cataracts cause light to scatter as it passes through the lens, giving it the appearance of a halo or streak around lights, which also is responsible for causing the inability to see contrasting objects. However, cataracts can be removed by surgery, in which the cloudy lens are removed and replaced by artificial lens.
I found an interesting article in which a cataract surgeon describes his own personal experience with cataract surgery.
In addition, I found a slideshow, which provides a visual and helpful guide to the causes, symptoms, and treatment of cataracts.