Get a copy of classes that are required for the schools you are interested in applying to.
Visit schools you are interested in over the summer after your second year. This gives you the opportunity to learn about the schools as well as let the schools know you are serious about them. Job shadow, volunteer, or attain a job with an optometrist.
Take the Optometry Admission Test (OAT) early in the year. You will have your scores before you begin to apply and will have ample time to retake the OAT, if necessary. You may want to visit your top choice schools again over the summer. Job shadow, volunteer, or attain a job with an optometrist.
Most schools accept students on rolling application basis, so have your application in as early as possible. Many schools have contract seats giving you reduced tuition, and applying early will enhance your chances of getting one of these seats.