A 63-year-old female patient comes to the Department

of Ophthalmology. Recently, she has been experiencing a significant

deterioration in her vision. Particularly with increased fatigue or in poor

light, she feels as if she is looking through foggy or dirty glass. In her

right eye, her vision is almost normal, but in her left eye she has this

sensation almost all the time. The cause of her difficulty is incipient

cataracts. In cataracts, vision is impaired due to clouding of the lens.

Chemical changes occur in the proteins that make up the lens, where the

otherwise transparent lens tissue begins to become opaque -

"clouding" - which appears on the outside as a whitening or greying

of the space behind the pupil. What are these lens cytoskeletal proteins

called?