This piece shows off the technical drawing skills of the artist and their ability to draw from a photograph. More accurate knowledge of the anatomy of the human eye and varied line thickness would improve this piece. The composition is interesting with an obvious focal point. The colours used for the rainbow within the iris are harmonious and well blended into a gradient.
Although not an original idea the intentions behind this piece are touching, giving the drawing an emotional and human connection that exceeds the artistic skills. The media used is commendable as it requires more effort than Photoshop.
My first critique, I hope it's okay! Clearly can see you spent a lot of time on this, and you can also tell you've had some meaning behind it (shown by the story in the description). Superbly detailed: the vessels in the eye are faint yet noticeable, the cornea is blended into the eye both sides very well and the colours are also blended with a clear quality. The pencil work is done very precisely, and it looks like you've used a range of pencils to get different tones too. I can't fault the eye really, I may say the part above the eye is a little too high and it makes the eye seem to be tall, but don't get me wrong this is magnificent. Great talent, keep at it!