The visual field is usually the same for large and small eyes, but ptosis or strabismus may affect the visual field.
The visual field is generally defined as the area of space that can be seen with the eyes and head fixed and the eyeballs looking straight ahead. The difference between large and small eyes is the extent to which the upper eyelid margin covers the pupil margin. If the upper eyelid margin is located at the upper edge of the cornea and covers the upper edge of the cornea by 1-2 mm, the patient’s field of vision is generally unrestricted and is normal.
If the coverage exceeds the upper corneal edge by 1~2mm but does not reach the upper pupil edge, the patient develops ptosis, which can result in a reduced field of vision. External light needs to enter the eye through the pupil in the center of the iris to be imaged. If the patient’s eye position is skewed and the upper eyelid covers part of the pupil, the field of vision may be affected to some extent.
It is recommended that patients with a reduced range of visual fields seek medical attention to evaluate their condition and follow the doctor’s instructions for treatment.