The hardening and yellowing of the lens caused by a cataract can result in vision changes that affect your daily functioning:

• Reduced ability to perceive contrast: Seeing an object clearly against a background of the same color – a white coffee mug on a light tablecloth, or a brown chair against a dark rug, for example – becomes more difficult and requires an increase in background contrast to make it "stand out."
• Problems with depth perception: Judging distances accurately – the height of a step or curb, or the depth of a bathtub, for example – requires closer attention. In addition, shadows and shadow patterns can be incorrectly interpreted as drop-offs, level changes, steps, or obstructions.
• Need for more light: As we get older, we generally need three to four times more light to perform everyday activities. Seeing clearly enough to read, write, sew, knit, or do home repairs usually requires a brighter, more focused light along with reading glasses or bifocals. This need for increased light occurs gradually, and most people aren't aware that their lighting requirements have changed over time.
• Increased sensitivity to glare: Although we need more light as we get older, too much light can also cause problems. Bright outdoor sunlight or reflected light from a hallway with highly polished floors can make it difficult to see clearly because too much light can also produce glare, which can interfere with seeing our surroundings clearly.
• Overall blurring: People, objects, and colors look hazy, cloudy, and "washed out." This lack of detail makes it difficult to tell time, read, watch television, see food on a plate, and walk safely indoors and outdoors, since depth perception may also be affected.

Some individuals with cataracts describe the effect as being similar to looking through a window that is hazy and streaked with dirt.