The correct spark plug and gap is crucial to proper ignition. Spark discharge is a breakdown in the air insulator between the electrode and ground. Yes - air is an insulator, a pretty good one at that. As voltage builds at the electrode, atoms in the air within the air gap gain electrons. This process is called ionization.
It's one of the reasons why our standard lenses are polycarbonate (thinner than standard lenses typically sold by other eyeglasses retailers). At Warby Parker, you can upgrade to high index lenses for an additional $30 whereas it typically costs $60 to $100 more.
If your eye doctor recommends and prescribes disposable bifocal contact lenses, an estimated per-box cost for these lenses is $50 to $70 (similar to the cost of disposable toric contacts). So again, an annual lens cost of $500 to $700 is not unusual if you wear the lenses daily and replace them every two weeks.