Physiology aspects

On visual system, either one of the eyes is closed or opened, both pupils will constrict when exposed to light. This is a normal reaction. When the light from ophthalmoscope was being moved from the eye, the pupils will begin to dilate and will constrict again to any light shine to it in order to avoid abnormality of light rays going inside the eyes.

As for visual acuity, the normal acuity is 6/6 in metre (m) or 20/20 in feet (ft). Subject A has visual acuity 20/30 for her right eye while 20/20 for her left eye. This means that subject A can see at a distance of 20 ft where a person with normal vision can see at 30 ft for subject A’s right eye while her left eye can see at a distance of 20 ft that normally can be seen at 20 ft. If a person is having a vision worse than 20/200 that cannot be corrected with possible lenses, that person is considered to be legally blind.

Legal blindness is also considered to happen to an individual who have a visual field of less than 20 degrees. In this experiment, subject A is normal where the range is between 85 degree and 90 degrees.



A person that is said to have astigmatism will not have a clear vision at certain distances. Subject A sharpest line is line 3 and line 9 where other line is said to look blurry. Therefore, subject A’s axis of astigmatism is line 12 and line 6 where this lines will be generally blurriest to subject A.

For colour blind test, a person with normal vision can recognize and identified the numbers or objects in the patterns of dots while those with red-green colour blind barely can identify it and mostly they will see is spots and sometimes interpret the dots to an incorrect numbers or objects. This is due to the absent of one of the cone cells in the retina or the cone has a different spectral sensitivity.

For the experiment done on the auditory system, the data recorded for the absolute threshold of hearing may be inaccurate due to the environmental disturbance hence subject A’s sensitivity of hearing decreasing for both ears. The presence of other noises such as the sound of the air-conditioner, footsteps and sound of a shaken tin of small rocks makes this experiment unsuccessful as it should be conducted in noiseless condition. However, other subjects’ data is taken to be compared. From Figure 1, it can be concluded that left ear have better sense of hearing as it can catches the sound of the ticking timer at quite a long distances than right ear probably should have.

Next on Rinne and Weber test, subject A is believed to have a normal ear where subject either can hear the loudest sound in air conduction than in bone conduction or bone conduction and air conduction are both equally reduced, maintaining the relative difference of both air condition and bone condition in sensor neural hearing loss. The sound is amplified and directed by pinna, eardrum and ossicles in air conduction whereas bone conduction bypasses some of the sound and allows the sound to be transmitted at a reduced volume directly to the inner ear albeit or through the bones of the skull to the opposite ear.