Blurred vision after pupil dilation

Most common Dry mouth (67%) drowsiness (less than 17%) transient impairment of eye accommodation including blurred vision and dilation of the pupils. Unilateral fixed and dilated pupil has been reported, apparently from accidentally touching one eye after manipulation of the patch. 

Methanol is metabolized to formaldehyde and formic acid, which injure the retinal cells and optic nerves, and lead to severe acidosis. Treatment delay increases morbidity. Thus, early recognition and management are crucial. Clinical features emerge up to 36 hours after ingestion. Nausea, vomiting, abdominal pain, headache, dizziness, paraesthesia, blurred vision, and diminished visual activity may occur, and coma supervenes. Dilated, unreactive, pupils predict permanent blindness. 

One man given 2.7 pg/kg became confused and developed hallucinations. The most common complaints of the other volunteers were of dry mouth, blurred vision, and drowsiness Several developed restlessness, an inability to sleep despite drowsiness, and anorexia. Of six men given 2.3 pg/kg, one had a decrease in performance in the Number Facility Test of more than 252, and three had dilated pupils. This dose Induced no tachycardia or hyperthermia. Of seven men given 2.7 pg/kg, five had decreased performance in the Number Facility Ttest of more chan 25%, three had dilated pupils, two had heart rates greater than 100 beats/mln, and one had a blood pressure above 140/90. There were no cases of hyperthermia (the report did not state the environmental conditions of the study). The mean heart rate after the larger dose was about 92 beats/min, whereas that after the smaller dose was about 79 beats/min. 

Intoxication may present as inebriation and drowsiness similar to ethanol use. Other symptoms are vomiting, diarrhea, delirium and agitation, back and abdominal pain, and clammy skin. Toxic effects usually follow a latent period of several hours. Formate inhibits mitochondrial cytochromes resulting in neurotoxicity. Ocular signs include blurred vision, dilated pupils, and direct retinal toxicity with optic disc hyperemia and ultimately permanent blindness [91]. Cerebral hemorrhagic necrosis has been reported [92]. Severe poisoning may result in Kussmaul respiration, inspiratory apnea, coma, and death. Urine samples may have the characteristic smell of formaldehyde. An elevated serum osmolal gap from methanol will be evident early in presentation but may disappear after approximately 12 hours. At this time, an elevated anion gap metabolic acidosis from retained formate may be evident. 

The clinical features are an initial mild inebriation and drowsiness followed, after a delay of 8-36 h, by nausea, vomiting, abdominal pain, dizziness, headaches and possibly coma. Visual disturbances may start within 6 h and include blurred vision, diminished visual acuity and dilated pupils which are unreactive to light. These effects indicate that blindness may occur and changes to the optic disc can be seen with an opthalmoscope. Severe depression of the CNS may occur at later stages due to accumulation of metabolites. 

C. Retinal toxicity occurs 9-10 hours after ingestion and includes blurred vision, impaired color perception, constriction of visual fields, and blindness. The pupils are often fixed and dilated. Fundoscopy may reveal retinal artery spasm, disk pallor, and macular edema. Although gradual recovery occurs, many patients are left with permanent visual impairment. 

Effects on human health reflecting neurological, cardiovascular, or gastrointestinal symptoms can be observed either if lupin seeds are eaten unripe or not debittered. Symptoms of intoxication after ingestion of lupin seeds with high alkaloids content appear 1-14 h after consumption and include dry mouth, muscular weakness, disturbed balance, sweating, palpitation, blurred vision, mydriasis (i.e., dilated pupils), urine retention, gastric and intestinal troubles, and abtmdant ventricular extrasystoles [45]. 

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