This is actually called CLOUDY EYES of rabbits.
As with humans and other animals, cloudy eye (cataracts) can become a problem for your rabbit as he grows older, and is a very serious condition that requires immediate veterinarian care.
Rabbits are often born with cloudy eye, in particular dwarf breeds. This condition can also develop due to light exposure, trauma, and for no apparent reason as your rabbit gets older. However, when a cataract develops it is usually because of bacterial infection. Additionally, the Encephalitozoon cuniculi (e. cuniculi) is a parasite that can cause cataracts.
Presently there are two treatment options available for rabbits with cloudy eye. One available treatment option is the use of prescribed medication, and the other treatment option is laser surgery. How your veterinarian will want to treat the condition ultimately depends on the root cause of it.