Cataract brunescens results due to deposition of -
In nuclear senile cataract, there may or may not be associated with deposition of pigment urochrome and/or melanin derived from amino acids in the lens.
Commonly observed pigmented nuclear cataracts are amber, brown (cataract brunescens) or black (cataract nigra) and rarely reddish(cataract Rubra) in colour.
Copper
Iron
Silver
Urochrome