today I will discuss about Harrisburg corneal reflex test harsh bark test is an objective test performed with a simple pen torch and gives rough objective estimation of angle of a manifest screen it uses first purkinje image to access element of ice or potential strabismas being an objective test it can be used in young and uncooperative patients or when physician in deviating eye is poor the harsh bark test is also known as the corneal light reflex test because in this test we assess the reflexive Point light source in patients eyes procedure of the test patient sits at a distance of 50 centimeter from The Examiner examiner turn on the pen light and direct it towards the mid lane of the nose that is middle of the eyes then instruct the patient to look at the light now examiner placing his eyes directly behind the pen light observe the corneal light reflex from the both eyes the degree of strabismas can be roughly estimated by measuring the decenteration of the reflex from the center of pupil in millimeters one millimeter of the deviation of the reflex is equal to 15 prism diameter remember these points one degree is equal to two prism reactors and one mm is equal to 7 degrees or 14 prism adapters now documentation observation reflection is centered in each people interpretation Ortho position or normal alignment [Music] observation reflection is decentered temporarily from the center of people interpretation isotropia [Music] observation reflection is decentered naturally from the center of people [Music] interpretation exotropia [Music] observation reflection is decentralized downward from the center of people [Music] interpretation hypertropia [Music] observation reflection is decentered upward from the center of people [Music] repetition hypertropia always remember the corneal reflex is decentral opposite to the deviation of ice if the eyes move in or Izu The Reflex will go out if the ice moves out or EXO then the reflex will move in now estimation of deviation by harsh Bar Cornell reflex test accuracy is less because this is an objective test and we are not using any prism to measure the deviation but it's quite good for rough estimation of deviation if the reflex is in between the center of people and people are emerging rough estimation of deviation is 7 degree or 15 prism adapter if the reflex is at pupillary margin the rough estimation of deviation is 15 degree or 30 prism reactor if the reflex is in between the people are emerging and limbus then the rough estimation of deviation is 30 degree or 60 prism diapers [Music] if the reflex is at limbus [Music] rough estimation of deviation is 45 degree or 90 Raptors if the reflex is at sclera more than 45 degree or more than 90 prism reactors [Music] [Music] foreign [Music] smartly [Music] foreign