Someone who has vision in only one eye can no longer use as a cue for the perception of depth and distance.

Binocular cues--particularly retinal disparity and binocular convergence

Binocular cues are information (depth/distance) taken in by both eyes. The two main types of binocular cues are retinal disparity and binocular convergence. 

Retinal disparity arises from the fact that our left and our right eyes, being a few centimeters apart, view images at slightly different angles. The two different images are merged into one and this allows us to perceive depth in the things we see around us. 

Binocular convergence is the simultaneous inward movement of both eyes in order to maintain a single binocular vision. The closer the object is, the more inward rotation is required for the eyes. The degree of rotation of the eyes helps the brain to interpret the distance of the perceived objects. 

Answer:

it provides an alternative energy pathway for the reaction to proceed.

explanation:

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.