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.
Typical costs: 1  Prices for contact lenses vary tremendously depending upon the type of lens. Disposable lenses, which are worn once and then thrown away, cost between $70 and $100 for a 90-day supply. 2  Extended-wear contact lenses are also disposable, but can be worn for up to three months before needing to be replaced.