queen's missing left eye on canadian one dollar bill

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My father has a one dollar canadian bill issued in Ottawa 1973 which he has been holding onto since 1975.  (Image attached.) It is in good condition, and has an ID # of GD9387854.  The queen's left eye is missing (in a perfectly circular manner), as in a printing error.  My father has asked me to investigate whether or not the bill has any value.  Can anyone help us out with this query? 

Thanks in advance for any information provided.

The circle is a missing planchette. Planchettes were small discs of paper embedded within the bank note paper. They were a feature of Bank of Canada notes until the Journey series, and can still be seen in Canadian Tire Money.

Planchettes can easily be picked out with a needle and sometimes they even fall out on their own. It's an interesting curiosity that your $1's missing planchette was right under the queen's eye, but it's not a printing error.