I feel that an art critic can help viewers to perceive, interpret and judge an artwork to a certain extent. The art critic’s review serves to augment one’s knowledge too. Yet, the art critic may have certain vested interests in promoting or denouncing a piece of artwork and hence viewers should heed their reviews with a pinch of salt.
For the new viewer of art or a new buyer of art pieces, an experienced critic can enable the audience to realise the positive valuable experiences the work of art affords. He can also draw your attention to the significance of each artwork. An example, 
Another good example whereby a critic can help us perceive and interpret a picture would be Picasso's “The Blind Man’s Meal’s" from his Blue Period. The painting is not merely a portrait of a blind man; it is also Picasso's commentary on human suffering in general. The work elicits affinities to Picasso's own situation at the time, when, impoverished and depressed, he closely identified with the unfortunates of society. 
Perhaps one concern of the viewer is the qualification of the critic. For example, an amateur critic can help one to perceive and interpret an artwork, but his review may not be accurate. He may not have a good understanding of the medium or movement and may result in new art appreciators having a misconception of the artwork. At the other end of the spectrum, a well-qualified art critic will have a better understanding of the history of the art movement as well as its nuances and styles. Interestingly, the adage “beauty is in the eyes of the beholder” holds true because the best judge for an artwork is the person himself. For instance, cubism is not exactly everyone’s idea of beauty. So I believe that judging the aesthetic and value of a piece of artwork is based more on a person’s individual liking. However, an art critic who understands cubism can help a viewer to perceive and interprete such artworks like the Houses at la Estaque by Braque in 1909,thereby influencing the way a viewer will judge the artwork. 
Even then, we have to appreciate that there can be different interpretations of a similar piece of artwork among critics themselves. For instance, James Risser felt that Van Gogh’s “Self-portrait With Straw Hat” was done when he was depressed. According to another critic, blue was used to experiment with different stokes and hues . This goes to show that what each critic perceives and interpret may be totally different from another, causing confusion.
However, the critic may attempt to further his own agenda to promote a particular artist by portraying the artwork in an even more positive light so as to entice the art collector. These critics may have a vested interest in promoting the art pieces on auction, such as the sale of a private cubism art collection in May and June 2011, in order to obtain profits for the auction house.
In conclusion, the indisputable role of the art critic is to help the viewer perceive, interpret and judge an artwork. However, one should be discerning when reading or listening to reviews as they may be of differing qualities or could perhaps be sugar-coated in order to serve the interests of the art critic himself. In the absence of the element of bias and in the presence of a reputable art critic, one can expect to gain tremendous insight with respect to perceiving and interpreting artwork. However, I believe that although an art critic can influence a viewer’s judging the artwork to a certain extent, most viewers will prefer to judge the artwork by their own life experiences.
