The Macula
The macula
has an important and naturally occurring protective yellow filter known as
macular pigment. A healthy
macula
is rich in the three carotenoids: lutein, zeaxanthin and meso--zeaxanthin. This layer of pigment acts as a protective shield against
oxidative stress, free radical and blue light damage.
Essentially
macular pigment is like a ‘sunscreen for the eyes’. However, due to longer life expectancy
macular pigment levels can deplete over the years causing age related changes to our central vision. As
blue light is part of normal vision, and oxygen use is required for life,
free radical damage is the cost of living, and is therefore unavoidable.
What is a photoreceptor?
Photoreceptors are special cells in the
retina
which are responsible for converting light into nerve signals. There are over 120 million photoreceptors in the human retina some of which are adapted to detect colour and others adapted for low light.