{'fraction_non_alphanumeric': 0.01878453038674033, 'fraction_numerical': 0.0027624309392265192, 'mean_word_length': 4.87987012987013, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
ABC of eyes

muscles the eyes become extorted on looking down, and the patient experiences torsional diplopia. This is sometimes accompanied by a convergent deviation on depression caused by the loss of abduction (which is the normal secondary action of the superior oblique muscles, to which Dr Sharland refers). In bilateral superior oblique muscle palsies depression of the ceres is also limited when the eyes are converged (and, hence, are in the adducted position). A patient may compensate for the difficulty in maintaining binocular single vision on looking down by lowering his chin so as to avoid the need to depress his eyes. Messrs A R Elkington and P T Khaw (30 July, p 347) stated that the assessment of intraocular pressure by palpation (digital tonometry) is done with the patient's eye closed and is useful only when the pressure is raised considerably. I suspect that these statements are cause and effect. Digital tonometry should be done with the patient's gaze directed downwards so that the sclera above the limbus can be felt through the thin flexible part of the upper eyelid above its tarsal place. When the eye is closed the globe is turned upwards (Bell's phenomenon) and only the cornea is available for palpation. The upper lid is not lowered so much, making it difficult to get the palpating fingertips above the tarsal plate, and there is always some associated contraction of the orbicularis oculi muscle, especially if the eye is painful. In these circumstances digital tonometry is almost impossible. If one does digital tonometry on every eye examined one's fingers soon become sensitive to even slight changes in intraocular pressure, although I would not suggest that this method of assessing the pressure is adequate for the diagnosis and management of open angle glaucoma.