Am I bound to serve a lease if it has no terms about me terminating early?

The lease is a contract between landlord and tenant.  Although the lease does not mention early termination by the tenant, you are still bound by the terms of your lease for the duration of your lease.  If you break the lease and move out now with eight months remaining, you will remain liable for the rent for the balance of the term of the lease or until the place is re-rented.  When the place is re-rented, your obligation to pay rent ends.  The landlord is required to mitigate (minimize) damages (the amount  the landlord claims you owe) and cannot allow the rental to remain vacant for the balance of the term of the lease without making reasonable efforts to find another tenant.  If the landlord does not make reasonable efforts to find another tenant, the landlord will have failed to mitigate damages and the landlord's damages will be reduced accordingly.  Reasonable efforts by the landlord to find another tenant will be determined by what other landlords in the area are doing to attract tenants; for example, posting a sign on the property advertising the vacancy, advertising the rental in the newspaper, in a local rental guide, online, etc.

If the landlord finds a new tenant, but charges the new tenant less rent than you were paying, you may be liable for the difference in rent for the balance of the term of your lease.  The landlord must have a valid reason such as market conditions, for charging the new tenant less rent.  If the landlord does not have a valid reason for charging the new tenant less rent, the landlord has failed to mitigate damages and the landlord's damages will be reduced accordingly, and you won't be liable for the difference in rent for the balance of the term of your lease.