trial frame being held by an optometrist during an eye exam

trial frame optometrist eye exam eyesight vision ophthalmology healthcare medical care optometry patient doctor clinic hospital health medicine diagnosis treatment prescription eyeglasses lenses correction test visual acuity ophthalmologist optician equipment instrument examination checkup professional problems myopia hyperopia astigmatism refractive error disease loss blindness optical lensometer phoropter autorefractor retinoscope ophthalmoscope