A. Nearsightedness is a common vision defect in which distant objects appear out of focus, while objects that are within close range can be seen clearly. People who are nearsighted find it difficult to focus on road signs or a screen in a movie theater, but have no problem reading their morning paper.Signs of nearsightedness include eye strain, headaches, squinting and blurred vision.
Farsightedness is a common vision defect in which distant objects can be seen clearly, while objects that are within close range appear out of focus. People who are farsighted may be able to read street signs from blocks away, but may have difficulty reading a book.Signs of farsightedness include aching, burning, red or tearing eyes, fatigue, headaches, “brow-aches,” poor eye-hand coordination and nervousness or irritability after sustained concentration on close vision work.
A. Color blindness is a common vision defect in which colors are not seen normally. People who are color-blind may not be able to identify the colors of their clothing or see colored text in a book. Some may not recognize any colors at all. Various health conditions, diseases, certain medications and poisoning can lead to color blindness.But in most cases, color blindness is an inherited trait that is present throughout life. About 8% of males have this defect, outnumbering color-blind women about ten to one. Most color-blind people find it difficult to see or distinguish greens from reds and vice versa. Others have problems with blues and yellows. Only a tiny minority of color-blind people cannot see any colors at all, and view the world in black and white. This minority is also very sensitive to bright environments and may have difficulty focusing on nearby objects. Many people over 60 years of age make up another category of partially color-blind people. As the lens of the eye ages, it tends to darken. Consequently, dark colors may be more difficult to identify and are easily mistaken.
A. Crossed-eyes, or (more accurately) eye misalignment, is a common vision defect in which either one or both eyes are turned inward, outward, upward or downward, and one or both eyes may show irregular movement. People with misaligned eyes may have difficulty catching a ball, because they cannot judge distances.They may see double and/or find it difficult to focus on objects because their eyes are not working together properly. Apart from the abnormal appearance of one or both eyes, the symptoms of this defect include squinting, blinking, headaches, nausea, eye pain and abnormal head posture.Misalignment of the eyes may be inherited and is especially common in children under 21 months old. Older children and adults may also develop this defect in association with an underlying disease, disorder or injury.
A. Astigmatism is a common vision defect in which eyesight may be blurred at all distances. People with minor astigmatism may believe to have a clear vision, but find they are squinting from time to time or suffering from headaches, eye strain, fatigue and blurred vision. An image viewed by persons with minor to moderate astigmatism may be blurry in some directions and clear in others (verticals, horizontals, obliques) and recognize better some letters shape (O vs T or X ). But people with severe or irregular astigmatism may see the world as a series of distorted images, as in a circus mirror.If you have astigmatism, welcome to the club! The vast majority of the world’s population has some astigmatism. The tendency to have or develop astigmatism is inherited and always accompanies nearsightedness or farsightedness. Sometimes both. As time goes by, astigmatism may gradually become more pronounced. Some say a light astigmatism oriented on vertical could be helpful for faster focus, particularly in our modern cities and spaces where horizontals and verticals are predominant.
Eyes and rugby balls
In astigmatic people, the cornea is not the usual half-sphere shape that it should be. In other words, instead of being shaped like half a soccer ball, the cornea is shaped more like half a rugby ball. When light rays hit the steep sides of the cornea, they are focused at two points instead of at one point on the retina (the nerve-rich lining inside the eye, where we “see”), producing blurred or distorted images.
A. Spots and floaters when looking at a blue sky or a white wall.Spots, floaters and flashes are all integral parts of the miracle of the inner eye and its life cycle. Spots and floaters are semi-transparent, thread-like strands, specks or brilliant crystals that float inside the eye. When we see spots and floaters, we may have the impression that foreign objects are in front of our eyes, but find that the objects dart away when we try to look at them directly.Spots and floaters come in many shapes and sizes. They may appear as tiny dots, round circles, long, thread- like strands, cobwebs or fuzzy clouds. We usually notice them when looking at a bright, blue sky or a blank, white wall. People of all ages see spots and floaters. Nearsighted people and people with eye injuries or inflammation see them more frequently. But in most cases, even though they may be bothersome, spots and floaters are harmless and fade away with time.Flashes are experienced by most everyone in late adulthood. Some flashes are caused by blood vessel spasms and can occur at any age. In either case, they may appear as straight or jagged vertical lightning streaks, shooting stars, fleeting white pin-points or brilliant blasts of light.
A. Presbyopia is a common vision condition in which it becomes increasingly difficult over time to focus on objects that are within close range. People with presbyopia find they have to hold reading material at arm?s length or move their computer screen back in order to bring text into sharper focus. Signs of this defect include eyestrain, headaches, eye fatigue, blurred vision and a diminishing ability to maintain focus on near objects.We we will all experience presbyopia sooner or later during our lifetimes. It generally occurs earlier in farsighted people than in nearsighted people, but no one develops presbyopia overnight! Presbyopia progresses gradually over the years, typically becoming more noticeable in the early to mid-forties.People who live in tropical climates and at sea level tend to develop this condition sooner.